Frequently Asked Questions

At Tsingke, our strength lies in our fully integrated gene synthesis value chain. From intelligent design and large-scale DNA synthesis, to dual QC verification, vector construction, and downstream applications, every step is under our control. This all-in-one capability ensures accuracy, reliability, and efficiency, helping our customers speed up their scientific innovation.

The common purification methods are DSL, OPC, PAGE, HPLC and Dual PAGE & HPLC.

No, they will not degrade. Dry primers can be stably stored at room temperature for at least two weeks. Since the average transport time is typically 5 days, the primers you receive will not be degraded.

The required OD value depends on the experimental purpose.

* 2 OD of a 20-base primer is sufficient for approximately 400 standard 50 μL PCR reactions.

* For applications like gene splicing or annealing for ligation, 1 OD is often sufficient. 

Key considerations for effective primer design include:

(1) Length: Generally between 15 and 30 bases.

(2) GC content: Between 40% and 60%.

(3) Base distribution: Bases should be randomly distributed.

(4) Complementarity: There should be no complementary sequences within the primer itself (hairpins) or between the two primers (primer dimers).

(5) Binding energy (∆G): Primers should have relatively high ∆G values at the 5' end, middle ∆G values, and low ∆G values at the 3' end.

(6) Product structure: The single strand of the amplification product should not form a secondary structure.

(7) Specificity: The primers must have high specificity for the target.

Low signal values are mostly due to high background fluorescence (for example, check the baseline-corrected or ROX-corrected raw curves). In probe-based detection, this is often caused by:        

* Poor probe design: Leading to insufficient quenching by the quencher group.

* Improper pairing: Incorrect matching of the reporter and quencher groups.

* Low labeling efficiency: The probe's fluorescence labeling efficiency is too low.

oligonucleotide synthesis utilizes solid-phase phosphoramidite chemistry. We synthesize a wide range of oligonucleotides, including:

(1) DNA oligos

(2) RNA oligos

(3) Probes

(4) siRNA

(5) sgRNA

(6) miRNA

(7) ASOs

(8) Various modified oligos

Crude oligonucleotides contain the desired product, failure sequences (shorter strands), and chemically modified by-products.

(1) Storage (Freeze-Dried): oligonucleotide primers in a freeze-dried state are highly stable and can be stored at -20°C for at least one year.

(2) Storage (Dissolved): Dissolved oligonucleotides can be stored as a 100 μM stock solution, aliquoted into multiple tubes, and kept at -20°C for at least six months (frequent freeze-thaw cycles may reduce shelf life).

Before use: Dilute the concentrated stock solution to the working concentration required for your experiments.

Before opening the vial, centrifuge it at 3000–4000 rpm for 1 minute to ensure the powder is at the bottom and prevent loss.

Add an appropriate amount of nuclease-free double-distilled water (pH > 6.0) or TE buffer (pH 7.5–8.0) to achieve a 100 μM stock solution for each OD.

Primer degradation occurs if the dissolving water has a low pH or is contaminated with bacteria or nucleases. Inadequate thawing and mixing when using the aliquot may also lead to inaccurate primer addition.

Recommendation:

* Aliquot the primers to avoid repeated freeze-thawing.

* Use 10 mMTris buffer (pH 7.5) to dissolve the primers.

* Note that sometimes the primer itself is not faulty, but the quality of other PCR materials (especially the template) may not be the same as previously used.

Synthesizing long-chain primers requires more reagents, especially for primers longer than 90 bases, which need combining. Due to the increase in reagent and synthesis costs, the price is higher.

The entire process from synthesis, QC to packaging can be highly customized. Customizable options include, but are not limited to:

(1) Packaging: In 1.5 mL, 15 mL, or 50 mL tubes.

(2) QC analysis: Capillary electrophoresis analysis, HPLC, PAGE, qPCR, full-wavelength scanning, and OD260/OD280 measurement.

(3) Documentation: Customized Certificate of Analysis (COA).

(4) Other: Provision of a 1 OD sample with each shipmentand specialized consumables.

Synthetic primers may appear yellowish-brown, white or transparent. This color is related to the base composition and the synthesis process. Primers with high A and G content and large OD value are usually yellowish-brown. Yellowish-brown primers will not have any effect on the experiment.

A common laboratory method is PAGE. Since primers are single-stranded DNA and can form complex secondary structures, denaturing PAGE is essential.

Gel Recommendations:

* Primers <12 bases: 20% polyacrylamide gel (7M urea)

* Primers 12 - 60 bases: 16% polyacrylamide gel (7M urea)

* Primers >60 bases: 12% polyacrylamide gel (7M urea)

Notes:

(1) Dissolve 0.2-0.5 OD primer with saturated urea solution (or add dry urea powder into primer solution until saturated) and heat denature (95°C, 2 min) before loading. The urea denatures the DNA and increases sample specific gravity for easier loading.

(2) Detect the bands with a fluorescent TLC plate under a UV lamp. Good purity is indicated by no impurities below the main band. (Sometimes due to insufficient denaturation, there may be bands above the main band, which are primer secondary structure bands.)

The OD value of a synthetic primer is determined by using a UV spectrophotometer at a wavelength of 260 nm and a 1 cm path length quartz cuvette.

* The solution must be diluted so that the optical density is between 0.2-0.8.

* The OD value of the stock solution must be calculated by multiplying the reading by the dilution ratio.

For example, the DNA was dissolved in 1 mL of water to create a stock solution. A 1:10 dilution of this stock (100 μL stock + 900 μL water) yielded an A260 of 0.2 when measured in a 1-cm path length quartz cuvette. This measurement corresponds to an original stock concentration of 2 OD.

The OD value of a synthetic primer is determined by using a UV spectrophotometer at a wavelength of 260 nm and a 1 cm path length quartz cuvette.

* The solution must be diluted so that the optical density is between 0.2-0.8.

* The OD value of the stock solution must be calculated by multiplying the reading by the dilution ratio.

For example, the DNA was dissolved in 1 mL of water to create a stock solution. A 1:10 dilution of this stock (100 μL stock + 900 μL water) yielded an A260 of 0.2 when measured in a 1-cm path length quartz cuvette. This measurement corresponds to an original stock concentration of 2 OD.

The OD value of a synthetic primer is determined by using a UV spectrophotometer at a wavelength of 260 nm and a 1 cm path length quartz cuvette.

* The solution must be diluted so that the optical density is between 0.2-0.8.

* The OD value of the stock solution must be calculated by multiplying the reading by the dilution ratio.

For example, the DNA was dissolved in 1 mL of water to create a stock solution. A 1:10 dilution of this stock (100 μL stock + 900 μL water) yielded an A260 of 0.2 when measured in a 1-cm path length quartz cuvette. This measurement corresponds to an original stock concentration of 2 OD.

As oligonucleotide length increases, synthesis complexity and the risk of incomplete sequences also increase. Unless specifically required, we recommend limiting primer length to 80 bases or less. At this length, the proportion of full-length product in a crude synthesis typically does not exceed 40%, and additional losses may occur during purification, resulting in reduced final yield.

With optimized synthesis conditions, primers of up to 145 bases can be produced; however, yields and purity decrease significantly at extended lengths, and such designs should be considered only when shorter alternatives are not feasible.

Agarose gel electrophoresis is unsuitable for analyzing synthetic primers. Since primers are single-stranded DNA, they easily form complex steric structures, leading to multiple or no bands on an agarose gel. Therefore, denaturing PAGE electrophoresis is the recommended method.

Modified oligonucleotides generally exhibit lower yields and higher production costs due to several inherent factors:

(1) Reduced synthesis efficiency: Modified phosphoramidites are often less chemically stable and exhibit lower coupling efficiency during synthesis, resulting in decreased overall yield compared to standard oligonucleotides.

(2) More stringent purification requirements: To ensure performance and purity, modified oligonucleotides typically require advanced purification methods such as PAGE or HPLC. These processes lead to additional material loss during purification.

(3) Higher raw material costs: Specialized modified monomers and reagents are significantly more expensive - often by orders of magnitude - than standard synthesis materials.

Together, these factors contribute to the higher cost structure and reduced yield commonly associated with modified oligonucleotides.

No. By default, synthesized oligonucleotides are delivered with a 5' hydroxyl (-OH) group rather than a phosphate. If phosphorylation is required, two options are available:

(1) Post-synthesis enzymatic phosphorylation

Customers may perform 5' phosphorylation using polynucleotide kinase (PNK) after receiving the oligonucleotides.

Custom phosphorylation during synthesis

(2) 5' or 3' phosphorylation can be incorporated during synthesis upon request as a value-added service.

(1) Photodamage risk

UV illumination used to visualize and excise gel bands can quench fluorescence or chemically degrade dye labels, compromising assay performance.

(2) Unpredictable gel migration

Fluorescent dyes alter the molecular weight and charge of oligonucleotides, leading to atypical migration behavior and making accurate band identification difficult using standard size markers.

For fluorescently labeled oligonucleotides, HPLC purification is strongly recommended, as it provides high purity while preserving the integrity and performance of fluorescent modifications.

Low signal values are mostly due to high background fluorescence (for example, check the baseline-corrected or ROX-corrected raw curves). In probe-based detection, this is often caused by:        

* Poor probe design: Leading to insufficient quenching by the quencher group.

* Improper pairing: Incorrect matching of the reporter and quencher groups.

* Low labeling efficiency: The probe's fluorescence labeling efficiency is too low.

Erratic peaks often result from contamination in the reaction system.   

* Confirm contamination using No Template Control (NTC) and No Reverse Transcriptase Control (NRC) results.

* Check potential sources such as water, oligonucleotides, enzymes, and the experiment settings.   

* Reagents exposed to strong light or high temperatures may degrade. It is recommended to compare results with fresh reagents.

Primers that have been resuspended may degrade or produce inconsistent results over time due to several common factors:

(1) Primer degradation: Resuspension in nuclease-contaminated water or solutions with non-neutral pH can lead to gradual chemical degradation or enzymatic cleavage, reducing primer integrity.

(2) Improper handling: Incomplete thawing, insufficient mixing, or repeated freeze-thaw cycles may result in uneven primer concentration, causing variability in pipetting and assay performance.

(3) Changes in other reaction components: Apparent primer failure may also be caused by deterioration or variation in other PCR reagents-most notably the DNA template - rather than the primer itself.

Recommended Best Practices:

(1) Resuspension buffer: Dissolve primers in nuclease-free 10 mM Tris-HCl (pH 7.5 - 8.0) to maximize stability.

(2) Aliquot and storage: Aliquot primer solutions into single-use or low-use volumes and store at -20°C to minimize freeze–thaw cycles.

(3) Thorough mixing before use: After thawing, vortex briefly and centrifuge to ensure a homogeneous solution prior to pipetting.

Generally not. Modern PCR techniques and high-temperature polymerases have been developed to solve most issues of amplification failure and low n efficiency. Failures are more commonly due to two main situations:

(1) RT-PCR: The quality of the RNA used in the RT reaction and the content of the target gene in the tissue/cell are critical.

For example, some repeat fragments, fragments with high GC content amplification, must use special amplification means to amplify.

(2) Amplification from the genome: Genes are single copies in the genome, so the amount of genomic DNA template must be strictly controlled. Too much genomic DNA can affect the Mg2+ concentration and pH in the reaction system.

No. Sequencing of non-specific fragments usually finds at least one primer sequence at both ends. Therefore non-specific amplification is typically the result of template contamination (e.g. contaminated genome in RNA) or unsuitable amplification conditions.

Tsingke ensures sample uniformity by isolating monoclonal clones. Each clone is validated by Sanger sequencing, covering the entire gene and at least 50 bp of the vector backbone upstream and downstream, which ensures the gene is correct and properly placed in the vector. The plasmid then undergoes NGS to verify the accuracy of the entire plasmid and detect any contamination. Before shipment, a strict QC review is conducted.

Capture probes are commonly classified based on their application areas, including:

* Cancer research probes

* Basic research probes

* Hematology-related probes

* Pathogen detection probes

* Genetic disease probes

* Methylation analysis probes

Successful multiplex PCR primer design requires careful consideration of the following factors:

(1) Primer length: Primers are typically designed to be 18-24 nucleotides long to ensure specificity while minimizing the risk of primer-dimer formation.

(2) Melting temperature (Tm): All primers included in a multiplex reaction should have similar Tm values to enable uniform annealing and efficient amplification under a single set of cycling conditions.

(3) 3'-End complementarity: Complementarity between primers, especially at the 3' ends, should be avoided to reduce the likelihood of primer-dimer formation and non-specific amplification.

(4) Stepwise optimization: Each primer pair should be optimized individually before being combined. Once pooled, primers should be mixed and further optimized incrementally to achieve balanced amplification.

Adhering to these principles helps improve specificity, efficiency, and reproducibility in multiplex PCR assays.

In multiplex PCR, multiple primer pairs are used simultaneously, making optimization of reaction conditions critical for balanced and specific amplification.

(1) Annealing temperature: Each primer pair has its own optimal annealing temperature. For multiplex reactions, the annealing temperature is typically set based on the lowest melting temperature (Tm) among all primers to ensure efficient binding and amplification across targets.

(2) Cycle number: Using the minimum number of PCR cycles required to obtain sufficient product helps maintain amplification efficiency and specificity, while reducing nonspecific products and amplification bias between targets.

Careful optimization of both annealing temperature and cycle number is essential for reliable and reproducible multiplex PCR performance.

In multiplex PCR, multiple targets are amplified simultaneously, increasing competition for key reagents such as DNA polymerase, dNTPs, and primers. If reagent concentrations are not properly optimized, amplification efficiency and balance between targets may be compromised.

Additionally, the simultaneous synthesis of multiple amplicons increases the overall demand on the polymerase, often requiring longer extension times than single-target PCR to ensure complete and efficient synthesis of all products.

Optimizing reagent concentrations and extension time is therefore essential to achieve uniform amplification, high specificity, and reliable results in multiplex PCR assays.

For multiplex PCR, primers are typically designed to be 18-24 nucleotides in length. This range provides a balance between specificity and efficient annealing, while minimizing the risk of primer-dimer formation. Longer primers are generally more prone to secondary structure formation and non-specific interactions, which can negatively affect multiplex PCR performance.

This issue is most commonly associated with the inherent limitations of chemical oligonucleotide synthesis. Synthetic primers are not 100% pure, and trace amounts of truncated or failure sequences may be present. These minor impurities can occasionally participate in PCR amplification and be carried through cloning and sequencing.

We recommend the following actions:

(1) Sequence additional clones: Re-pick and sequence one or more additional colonies. In most cases, the initially sequenced clone originates from a PCR product amplified by a minor impurity, while other clones contain the correct sequence.

(2) Contact technical support if the issue persists: If the same primer-region error is observed consistently in 2-3 independent clones, the primer batch itself may be the source. Please contact our technical support team for further assistance. We will arrange prompt resynthesis or replacement of the primer at no additional cost.

We specialize in synthesizing RNA oligos up to 180 nucleotides in length. Types mainly include: siRNA, sgRNA, miRNA, ASO, and various modified RNAs.

All RNA oligonucleotides undergo rigorous quality control:

(1) Mass spectrometry (MS): Every batch is verified by MS to confirm identity and mass accuracy.

(2) HPLC purification: Available for applications requiring >90% purity.

(3) Nuclease-free and integrity checks: Gel electrophoresis and functional validation are optional upon request.

We guarantee sequence accuracy, modification integrity, and high batch-to-batch reproducibility.

Our custom RNA oligonucleotide services offer a high degree of flexibility, allowing you to tailor each stage of the workflow-from synthesis and quality control to packaging and delivery-to meet your specific requirements.

In addition to standard RNA synthesis, we provide integrated, end-to-end solutions for small nucleic acid screening and targeted delivery. Our capabilities support high-throughput workflows and comprehensive performance evaluation, including:

* Efficacy assessment: Analysis of mRNA and protein knockdown efficiency.

* Stability and safety evaluation: Assessment of oligonucleotide stability, off-target effects, immunogenicity, and cytotoxicity.

These services deliver reliable, highly reproducible results, enabling confident identification and optimization of lead RNA candidates with enhanced silencing performance.

Several delivery strategies are commonly used, including:

* Lipid-based transfection (liposomes)

* Ligand conjugation (e.g., peptides, GalNAc, cholesterol, fatty acids, aptamers, antibodies)

* Electroporation

* Gymnotic (naked) uptake

The optimal delivery method depends on the cell type, oligonucleotide chemistry and modifications, and the specific experimental or therapeutic application. Please contact us for technical guidance tailored to your system.

We offer a wide range of RNA modifications:

(1) Stability enhancements: 2'-O-methyl (2'-OMe), 2'-fluoro (2'-F), phosphorothioate (PS) bonds

(2) Functional handles: 5'/3' amino (NH2), thiol (SH), biotin, azide, DBCO

(3) Labels & detection: Fluorescent dyes (FAM, Cy3, Cy5), quenchers (BHQ)

(4) Specialty bases: Pseudouridine (Ψ), 5-methylcytidine

These modifications improve stability, specificity, delivery, and functionality for applications such as RNA therapeutics and diagnostics.

Commonly used fluorescent dyes for RNA labeling have well-defined excitation (absorption) and emission maxima. Typical values are listed below:

* FAM: Maximum absorption at ~495 nm; maximum emission at ~520 nm

* Cy3: Maximum absorption at ~550 nm; maximum emission at ~565 nm

* Cy5: Maximum absorption at ~643 nm; maximum emission at ~667 nm

Note: Exact wavelengths may vary slightly depending on the dye supplier, conjugation chemistry, and measurement conditions.

(1) The product is shipped in the form of lyophilized powder, the dry powder is attached to the wall of the tube and is easily dispersed when opened, so please centrifuge the tube for a few seconds before dilution to make the product gather at the bottom of the tube and open the cap carefully, cover the tube after dissolution, vortex and shake to mix to make full dissolution. It is recommended to store at -20°C or below, avoid repeated freezing and thawing, and keep in separate containers. Centrifuge instantly before use and prepare 20~100 μM storage solution with RNase-free Water or ddH2O, the average molecular weight of siRNA is 13300.

(2) RNA handling rules should be strictly followed and RNase-free lab supplies should be used for experimental operations to avoid degradation of RNA. Please keep on ice when using this product.

(3) For RNA with fluorescent marker, we use brown centrifuge tube to pack, because the fluorescent marker is sensitive to light, it must be stored away from light.

To ensure optimal performance and stability of siRNA products, please follow the guidelines below:

1. Reconstitution and Storage

siRNA is supplied as a lyophilized powder and may adhere to the tube walls during shipping. Before opening the tube, briefly centrifuge to collect the material at the bottom. Open the tube carefully to avoid sample loss.

* After adding solvent, cap the tube securely and mix thoroughly by gentle vortexing to ensure complete dissolution.

* Reconstitute using RNase-free water or ddH2O to a recommended stock concentration of 20-100 μM.

* Store reconstituted siRNA at -20°C or below. Avoid repeated freeze-thaw cycles by aliquoting the solution into single-use portions.

* Before each use, briefly centrifuge to collect the solution at the bottom of the tube.

2. RNase-Free Handling

Strict RNA-handling practices must be followed. Use only RNase-free consumables and reagents to prevent degradation. During experimental procedures, keep siRNA solutions on ice whenever possible.

3. Fluorescently Labeled siRNA

Fluorescently labeled siRNA is packaged in light-protective (amber) tubes. Because fluorescent dyes are light-sensitive, samples must be protected from light during storage and handling.

Following these recommendations will help maintain siRNA integrity and ensure consistent experimental results.

Positive controls: These are verified siRNAs targeting housekeeping or reporter genes (e.g., GAPDH, ACTB, GFP/EGFP). They are used to assess the feasibility of the entire experimental system (transfection, RNA extraction, QC, etc.). We provide effective siRNA positive controls targeting GAPDH, ACTB, GFP/EGFP.

Negative controls: These are non-specific siRNAs used to demonstrate the specificity of siRNA effects. They can be universal or scrambled sequences based on requirements.

Yes. Negative control results are generally expected to be consistent across groups. Significant variation may indicate experimental or technical issues.

However,, genes involved in stress or immune responses can be sensitive to minor environmental or handling differences, which may cause variability even in negative controls.

If substantial deviations are observed, we recommend reviewing experimental conditions, sample handling, and assay reproducibility to determine whether the variation is biological in nature or the result of technical factors.

The two most common reasons are low transfection efficiency and suboptimal siRNA sequence design.

(1) Check transfection/improve efficiency: If you are using siRNA for the first time or working with a new cell line, we recommend testing and optimizing the transfection efficiency. If you have already optimized the transfection conditions and the problem persists, consider switching to a different transfection reagent or method.

(2) Evaluate siRNA sequence design: If the transfection efficiency is optimized but silencing effect is still poor, the sequence design may be ineffective.

Under normal conditions, FAM-labeled oligonucleotides emit green fluorescence (excitation ~495 nm) and Cy3-labeled oligonucleotides emit red fluorescence (excitation ~550 nm). If no fluorescence is detected after transfection, please consider the following factors:

(1) Excitation settings: Verify that the microscope or imaging system is set to the correct excitation and emission wavelengths (FAM: ~495/520 nm; Cy3: ~550/565 nm).

(2) Post-transfection washing: Cells should be washed promptly after transfection. Delays may reduce fluorescence intensity due to dye diffusion or degradation.

(3) Storage and handling: Improper storage or prolonged light exposure can lead to siRNA degradation or fluorophore quenching. Fluorescently labeled oligonucleotides, especially FAM, must be protected from light and stored as recommended.

(4) Medium replacement: Ensure that fresh culture medium is replaced in a timely manner after transfection to maintain cell health and signal stability.

This can be due to:

* Poor cell health: Ensure cells are in optimal growth condition.

* Cytotoxicity: High concentrations of siRNA or transfection reagents can be cytotoxic; adjust concentrations or switch to a less toxic reagent.

* Purity: Low-purity siRNA may contain impurities that affect cell viability.

* Transfection time: Prolonged transfection times can exacerbate cell death. 

Low transfection efficiency can result from several common factors:

(1) siRNA quality: Impurities or RNase contamination can reduce activity. Always use high-purity siRNA and RNase-free (e.g., DEPC-treated) consumables and reagents.

(2) Complex concentration: Suboptimal ratios or concentrations of the siRNA-transfection reagent complex may limit uptake. Optimization is recommended.

(3) Serum interference: Serum can inhibit complex formation. Prepare the transfection mixture in serum-free medium.

(4) Antibiotics in medium: Antibiotics may negatively affect transfection efficiency and should be omitted during transfection.

siRNA-mediated RNA interference is transient. Gene silencing typically persists for several days, and analyses are recommended within 3-4 days post-transfection.

Optimal detection window:

* mRNA levels: 24-48 hours post-transfection

* Protein levels: 48-72 hours post-transfection

The exact timing may vary depending on the target gene and cell type.

Transfection efficiency is primarily determined by the cell type and the transfection method, rather than the siRNA sequence itself. As a result, efficiency can vary significantly between different cell lines, even when using the same siRNA.

No. While our siRNA products are typically designed to achieve ~70% knockdown, an interference efficiency of ~60% is still considered biologically meaningful. Many published studies accept this level of knockdown, especially if it results in clear phenotypic or functional changes in the cells. In most cases, knockdown efficiency can be further improved by optimizing transfection conditions and the overall experimental setup.

siRNA acts directly on mRNA, making mRNA level detection the most direct detection indicator of its effect. While clients often want to see a corresponding drop in protein, an mRNA decline level does not always correlate exactly with the protein decline level. Possible reasons include:

(1) Assay time: The mRNA decline may not yet be reflected in the protein change, or the change may not be sufficient for detection. Protein and functional assays should be pushed back slightly.

(2) Cellular balance: Gene expression in cells is complex. The down-regulation of mRNA level is not exactly positively correlated with the down-regulation of protein level.  

Cells differ in transfection efficiency, endogenous gene expression levels, and other cellular factors that influence siRNA activity. As a result, the same siRNA may not produce identical knockdown effects across different cell types.

HPLC-purified sgRNAs support the same modifications as standard desalt preparations. These include common guide RNA modifications such as RNA, 2'-O-Methyl bases, and phosphorothioate linkages as well as newer options like 2'-fluoro and DNA base substitutions, within typical complexity limits.

Chemically synthesized sgRNA offers several key advantages:

(1) Higher editing efficiency: Studies show chemical synthesis achieves higher editing efficiency, compared to IVT sgRNA.

(2) Lower cytotoxicity: IVT sgRNA carries a 5'-triphosphate modification, which can trigger innate immune responses and cytotoxicity. Chemically synthesized sgRNA avoids theses off-target immunostimulatory effects.

(3) Enhanced stability: Chemical synthesis allows the incorporation of stabilizing modifications (e.g., phosphorothioate (PS) bonds and methoxy groups). Moreover, the chemical synthesis process ensures higher batch-to-batch consistency and reproducibility.

(4) Ease of use: Chemically synthesized sgRNA is ready to use upon delivery, while IVT sgRNA requires a multi-step, 2-3 day production process that , incurs greater time and economic costs.

Using synthetic sgRNA eliminates the need for annealing crRNA and tracrRNA before application. More importantly, studies suggest that long single-stranded sgRNA exhibits greater stability and higher genome-editing efficiency when complexed with Cas9 compared to the crRNA:tracrRNA duplex.

The most commonly used modification in antisense oligonucleotides is the phosphorothioate (PS) backbone, which enhances resistance to nuclease degradation.

A full PS backbone is often applied to improve stability, extend circulation time, and enhance cellular uptake, particularly in the absence of delivery agents. However, PS modification may slightly reduce melting temperature (Tm) and increase non-specific protein binding, which in some cases can contribute to immune-related effects.

The recommended starting transfection concentration for ASOs is 50 nM, with target gene analysis typically performed 24-72 hours post-transfection. In practice, the optimal concentration usually falls within the 10-100 nM range and should be determined by dose-response (gradient) optimization based on the specific cell line and ASO chemistry.

ASO silencing efficiency can be enhanced by optimizing several key factors:

(1) Improve transfection efficiency: Optimize the transfection reagent, conditions, and cell type to maximize ASO uptake.

(2) Optimize ASO concentration: Perform dose-response studies to identify the most effective concentration with minimal toxicity.

(3) Redesign the ASO sequence: If target RNA secondary structures limit access, alternative target sites or sequences may significantly improve silencing performance.

There are several different ways to introduce oligos into cells, including use of liposomes, attaching the oligo to a ligand (e.g. peptides, GalNAc, cholesterol, fatty acids, aptamers, antibodies etc.), electroporation, and gymnotic (naked) delivery.

The best method depends on the type of cells and types of modifications on the oligo, as well as the intended use of the ASO. Contact us for more information.

The most commonly used purification methods are PAGE and HPLC.

For most commonly used modifications, overall stability and degradation profiles are comparable to those of unmodified oligonucleotides. However, comprehensive long-term stability data are not available for every modification.

Recommended storage practices:

(1) Store oligonucleotides in lyophilized form at -20°C for maximum shelf life.

(2) After reconstitution, use TE buffer (10 mM Tris, 0.1 mM EDTA, pH 7.5-8.0) rather than water to improve stability, particularly at higher temperatures.

(3) Protect from light at all times and avoid UV exposure, especially for light-sensitive modifications.

(1) Stability and Efficiency: Modified monomers are less stable and have longer coupling times, resulting in lower efficiency and yield.

(2) Purification: They require intensive purification methods like PAGE or HPLC, leading to significant material losses.

(3) Raw Material Cost: The raw materials for modified primers are much more expensive, often hundreds of times more than those for general primers.

Commonly used fluorescent dyes include FAM, TET, HEX, TAMRA, ROX, Cy3, and Cy5. These dyes cover a broad range of excitation and emission wavelengths and are widely applied in PCR, hybridization assays, and fluorescence-based detection.

Fluorescently labeled oligonucleotides are highly sensitive to degradation from natural light and ozone. To maintain stability and prevent photobleaching, always store these oligonucleotides in the dark (e.g., in brown or opaque tubes or foil covering) and minimize their exposure to sustained light sources during handling.

Dual-labeled qPCR (TaqMan®-style) probes can use different quenchers, which primarily differ in background fluorescence and spectral range:

* TAMRA is a fluorescent quencher. Because it emits fluorescence itself, it can contribute to higher background signals and reduced assay sensitivity.

* Eclipse and BHQ (Black Hole Quencher) are non-fluorescent quenchers (NFQs). They do not emit light, resulting in lower background and a higher signal-to-noise ratio.

Spectral compatibility in multiplex qPCR:

* Eclipse provides broad quenching coverage (~390-625 nm) and is compatible with common dyes such as FAM, HEX, TAMRA, and ROX.

* BHQ quenchers (e.g., BHQ-1, BHQ-2, BHQ-3) cover an even wider spectral range (from ~430 nm into the near-infrared), supporting dyes such as Cy3 and Cy5.

Recommendation:

For high-sensitivity assays and multiplex qPCR, non-fluorescent quencher-based probes (Eclipse or BHQ) are generally preferred over TAMRA.

Amino modification introduces a reactive-NH2 group into an oligonucleotide, enabling covalent coupling to dyes, biotin, or solid surfaces.

Key considerations:

5' Aminolinker (C6) is incorporated via phosphoramidite chemistry on the 5' sugar, not on the terminal base.

The amino group absorbs at 210 nm, not 260 nm, and therefore cannot be visualized by standard gel electrophoresis.

3' Aminolinker (C7) is compatible only with selected 5' modifications (e.g., FAM, HEX, TET, fluorescein, biotin, phosphate) and is incompatible with dyes that also require an amine (e.g., Alexa Fluor® dyes).

Amino modification is a simple and cost-effective strategy; 5' C6-NH2 is recommended for most applications.

Biotin-modified oligonucleotides leverage the strong biotin-streptavidin interaction, enabling diverse applications in research and diagnostics. Key uses include:

* Non-radioactive immunoassays for protein detection

* Intracellular chemical staining and cell separation

* Nucleic acid isolation and hybridization to detect specific DNA/RNA sequences

* Probes for studying conformational changes (e.g., in ion channels)

* Immobilization on solid-phase surfaces (e.g., beads, chips)

Common stability-enhancing modifications include:

(1) 2'-O-Methyl (2'-OMe): Increases nuclease resistance and overall stability.

(2) 2'-Fluoro (2'-F): Enhances binding affinity and enzymatic stability.

(3) Phosphorothioate(PS) backbone: Improves resistance to nuclease degradation.

Modification choice depends on the application objective:

* Stability: 2'-OMe, 2'-F, or LNA

* Delivery: GalNAc or cholesterol

* Epigenetic studies: 5-methyl-dC or 5-hydroxymethyl-dC

* High-affinity binding: LNA or cEt

* Conjugation or labeling: Biotin, amino, or thiol modifications

They enable the development of advanced therapeutics by:

(1) Enhancing target engagement and specificity (e.g., LNA, cEt)

(2) Improving pharmacokinetics (e.g., GalNAc for liver targeting)

(3) Reducing immunogenicity (e.g., 2′-OMe, pseudouridine)

(4) Facilitating efficient delivery (e.g., cholesterol conjugation)

The choice depends on your goal:

For stability: Choose 2′-OMe, 2′-F, or LNA

For delivery: Consider GalNAc or cholesterol

For epigenetics: Use 5-methyl-dC or 5hmdC

For high-affinity binding: LNA or cEt are ideal

For functional conjugation: Biotin, amines, or thiols may be used

These are chemical alterations made to the natural sugar-phosphate backbone of oligonucleotides. They are designed to enhance properties such as nuclease resistance, stability in biological environments, and the ability to attach other molecules or enable site-specific cleavage.

No. Oligonucleotides are synthesized with a 5'-hydroxyl (OH) group by default. If 5' phosphorylation is required, it can be performed enzymatically using polynucleotide kinase (PNK) or requested as a custom 5' or 3' modification at the time of ordering.

Several chemical modifications enable efficient conjugation:

* Maleimide: For selective covalent coupling to thiol (-SH) groups on proteins.

* Aldehyde or carboxyl: For reactions with amine (-NH2) groups on proteins or surfaces.

* DBCO/Azide: For highly specific, biorthogonal click chemistry reactions.

To maintain stability and performance, spacer-modified primers should be stored as follows:

(1) Protect from light: Use opaque or light-blocking containers.

(2) Low temperature: Store at -20°C or below.

(3) Dry conditions: Keep tightly sealed, preferably with a desiccant, to limit moisture and oxidation.

(4) Minimize freeze-thaw cycles: Aliquot upon receipt to avoid repeated freezing and thawing.

A dSpacer is an abasic-site analog that mimics a natural nucleotide lacking a base. It is primarily used in structural and mechanistic studies to investigate how enzymes-such as those involved in DNA repair-recognize and process damaged DNA. It can also introduce localized flexibility into an oligonucleotide.

Selection depends on the required spacing and application:

* Spacer C3: A short, 3-carbon linker, often used as a minimal spacer or to block 3'-end extension.

* Spacer C6: A widely used, versatile 6-carbon linker suitable for attaching fluorophores, biotin, and other labels.

* Spacer C12: A longer 12-carbon linker, chosen when greater separation or reduced steric hindrance is required.

We require the DNA or amino acid sequence you need synthesized.If codon optimization is required, specify the host species. Additionally, indicate any required restriction sites at the 5' and/or 3' ends, any internal modifications to avoid, and if you need additional sequences added (e.g., Kozak sequence, stop codons, etc.).Or you can download the "Tsingke Gene Synthesis Order Form" from our website and email it to info@tsingke.com.cn.Our technical support team will promotly estimate the pricing and turnaround time for you and send you a quotation shortly.

To help us design the most effective shRNA, please provide:

Gene information: Official gene name (Gene Symbol), species or Gene ID, and the target sequence.

Vector preference: The vector you would like the shRNA sequence to be cloned into. You may select from our available vectors (based on selectable markers, etc.) or provide your own vector.

Or you can download the "Tsingke shRNA vector construction Order Form" from our website and email it to info@tsingke.com.cn. Our technical support team will promotly estimate the pricing and turnaround time for you and send you a quotation shortly.

Download the "Tsingke Gene Synthesis Order Form" from our website, complete the “Gene info”, “Cloning vector”and“Plasmid preparation”section, and send it via email to info@tsingke.com.cn to place your order.

Yes, all customers' information will be kept confidential.

Yes, Tsingke also provides protein expression and purification services for synthesized genes, offering six major protein expression systems: E. coli protein expression system, Bacillus subtilis protein expression system, yeast protein expression system, insect cell protein expression system, mammalian cell protein expression system, and prokaryotic cell-free protein expression system.

Yes, Tsingke offers free codon optimization.

Codon optimization enhances gene expression by using preferred codons and avoiding rare ones for a specified host. This optimization correlates strongly with improved gene expression levels. Tsingkes unique Geneoptimizer software supports optimization for tens of thousands of hosts and offers customized services. Key optimization parameters include codonpreference. GC content, restriction enzyme sites (deletion), poly structures, and sequence repeats.

By default, we provide pUC57 vectors containing Amp (ampicilin) for free. we also offer a library of over 200 vector options available for free.

Generally, the default clone is between EcoRⅠ and Hind Ⅲ. If you have particular needs, please note and we can select other suitable cloning sites according to the experimental needs based on your sequence.

Yes, you can use your own vector. it is recommended to ship your vector in advance; otherwise, the turnaround time may be extended by 5 calendar days to verify the vector.

We need you to ship at least 2 μg of the plasmid and provide the full sequence information of the vector.lf the full sequence is not available, please provide at least 200 bp upstream and downstream of the cloning site, along with the vector's antibiotic resistance information.

No, the order defaults to providing 4 μg of plasmid dry powder. This plasmid is not recommended for direct transfection into cells or protein expression. If you need to conduct related experiments, please perform plasmid transformation, then isolate a single colony for cultivation, and use a plasmid extraction kit that meets the required standards to extract high-quality plasmid. Our company also provides plasmid extraction services. If you have higher requirements for the plasmid, you can select our plasmid extraction service simultaneously when placing your order.

The synthesized plasmid can be stored for one vear. Customer-provided vectors that are free of issues will also be stored forone year. During the storage period, you can use the plasmid for site-directed mutagenesis, cloning, or other services.

If there are any quality issues within one month of receipt,we will provide a free replacement. Overseas shipping fees will be charged separately, or the plasmids can be sent with other orders.

High and low GC content, repetitive sequence:

Solution: Divide the sequence into small segments to reduce the impact of structure, and choose the optimal connectionsolution, such as enzyme digestion and ligation and multi-segment recombination.

Long sequences

Solution: use multi-segment recombination to construct divided gene fragments, and combine them with vitro and vivo assembly.

Special parts of vectors (e.g. ccdB, LTR)

Solution: Use different competent cells corresponding to different parts of vectors, such as DB3.1, which renders the strain resistant to the toxic effects of the ccdB gene, the recombination-deficient Stbl series, etc.

Other unpredictable dlificulties, such as genetic instability and toxicity, and the introduction of random mutations and deletions.

Solution: Try different competent cells.

Tsingke ensures sample uniformity by isolating monoconal clones, Each clone is validated by Sanger sequencing, covering the entiregene and at least 50 bp of the vector backbone upstream and downstream, which ensures the gene is correct and properly placed inthe vector. The plasmid then undergoes NGS to verify the accuracy of the entire plasmid and detect any contamination. Beforeshipment, a strict OC review is conducted.

A tube containing approximately 500 ng of lyophilized DNA, lectronic Certificate of Analysis (COA), sequencing chromatograms (.abi files) and Target Sequences (.seq files)if sequencing validation is needed.

We provide one tube of lyophilized plasmid (stored at -20°C).

Our company defines long DNA sequences as those exceeding 10 kb. For sequences ranging from 10 kb to 30 kb, yeastassemoly methods are usedto first construct them into the pcc1413 vector before transferring them to your specified targetvector. sequences exceeding 30 kb will be directly constructed into the pcc1413 vector.

Efficient construction: Rapid generation of shRNA expression plasmids via gene synthesis, eliminating tedious cloning steps.

Professional optimization: Customized design for any gene from any species, with sequence optimization to enhance knockdown efficiency and minimize off-target effects.

Versatile vectors: A wide range of lentiviral backbones available; shRNA can be delivered by direct transfection or packaged into lentiviral particles for infection.

Easy selection: Vectors carry common resistance markers (e.g., PURO/NEO) for stable cell line establishment; fluorescent markers (e.g.,GFP/mcherry) allow real-time monitoring of transfection/infection efficiency and enable flow cytometry sorting.

Yes, Tsingke offer end-to-end services from plasmid to ready-to-use viral particles, including packaging, concentration, and titer determination. Lentivirus, AAV, and adenovirus systems are available, delivering high-titer viral particles ready for your experiments.

Download the "Tsingke Gene Synthesis Order Form" from our website, fill in the relevant fields according to your needs, and send it via email to info@tsingke.com.cn to place your order.

a. Templates: Provide and send us the template plasmid(≥2μg). If the plasmid was constructed by Tsingke and the order was placed within the last year, you do not need to provide it again.

b. Vector details: Choose from our 200+ free vectors or provide your vector.

c. Provide the sequences and resistance information for both template and vector, along with the target sequence and cloning siteinformation.

d. Order Form: Download the "Tsingke Gene Synthesis Order Form" from our website, fill in the relevant fields according to your needs,and send it via email to info@tsingke.com.cn to place your order.

No, the template sequence needs to be first constructed into a T-vector or another vector. then, amplify using the plasmid asthe template. Alternatively, you can choose our gene synthesis service by simply providing the DNA sequence.

a.DNA template: Please send us your template

b.Information: The sequence of the template including the target gene and vector information, mutation specifications.

c.Order Form: Download the "Tsingke Gene Synthesis Order Form" from our website, fillin the relevant fields according to your needsand send it via email to info@tsingke.com.cn to place your order.

The pricing for site-directed mutagenesis is evaluated and quoted based on the specific location of the mutation sites and the numberof mutations (all mutations within a 30-base region will be considered as one mutation).

Tsingke provides high-quality plasmid extraction services with Research Grade and Transfection Grade to meet diverse experimental needs.

We provide the following two options:

a. Gene synthesis + plasmid preparation: Synthesize your gene by Tsinkge our and then proceed with plasmid preparation.

b. Plasmid preparation only: You need to ship the target plasmid to us.

Download the "Tsingke Gene Synthesis Order Form" from our website, fillin the relevant fields according to your needs, and send it via email to info@tsingke.com.cn or gene@tsingke.com.cn to place your order.

Yes, Tsingke provides transfection-grade plasmid preparation services with low endotoxin levels and high supercoiled DNAcontent, suitable for cell transfection, gene therapy, and gene editing. Endotoxin levels can be selected as< 0.1 Eu/μg, <0.01 EU/μg, or <0.005 EU/μg.

Tsingke offers an integrated solution from gene synthesis to plasmid preparation, ensuring high-quality plasmids delivered in a seamless and efficient workflow. This one-stop service saves time, reduces experimental complexity, and guarantees accuracy for your downstream applications.

Adeno-associated virus(AAV):Suitable for long-term gene expression and applications with high safety requirements (e.g., gene therapy).

Advantages: Long-term expression, high safety.

Disadvantages: Lower transduction efficiency, small gene capacity.

Lentivirus(LV):Suitable for stable transduction and long-term gene expression (e.g., cell therapy).

Advantages: High transduction efficiency, broad cell type applicability, long-term expression.

Disadvantages: Potential genome integration, safety risks.

Adenovirus (ADV):Suitable for short-term expression and large-scale cell transduction (e.g., vaccine development).

Advantages: High transduction efficiency, suitable for large-scale production.

Disadvantages: Short-term expression, can trigger immune response.

Choose the appropriate vector based on your experimental needs.

Common methods for gene overexpression:

Overexpression plasmids: Introduce the target gene into cells through plasmid transfection for overexpression.

Overexpression lentivirus: Use lentiviral vectors to stably transduce the target gene, suitable for long-term gene expression.

CRISPRa transcriptional activation system: Utilize CRISPR technology to activate the expression of endogenous genes, offering precise regulation.

Each method has its own characteristics, and the choice should be based on the experimental objectives and cell types.

Turnaround time varies by vector type and project scale. Typically, AAV, LV, and AdV vectors can be delivered in as fast as 12–18 business days. Larger-scale or customized projects may take longer.

No. Our service includes plasmid preparation, where we clone the gene or sgRNA cassette into an appropriate transfer plasmid and prepare high-quality DNA.

Yes. For each category of viruses (AAV, ADV, lentivirus, etc.), clients can opt for a guarantee service to ensure the viral vectors meet expected performance standards.

Yes. We offer custom stable cell line construction, including knockout, overexpression/interference, point mutation, and knock-in cell lines.

• Delivered as frozen or cultured cells (≥1×10⁶ cells per vial)

• Turnaround time: 6–11 weeks depending on cell type

• Quality verification: Sanger sequencing, qPCR, or protein-level validation

• Includes positive clones and, when applicable, control lines ready for downstream experiments

The GFP fluorescence intensity in target cells depends on several factors, including the number of viral particles transducing the cells, the proliferative state of the cells, the cell type, and the observation time. Generally, the higher the number of viral particles transducing the target cells, and the faster the cell proliferation, the stronger the GFP fluorescence. For cells with faster proliferation, GFP expression typically peaks 48 to 72 hours after viral transduction. For slower proliferating cells, the GFP expression time will be extended.

At Tsingke, we generally improve transduction efficiency by increasing the MOI (multiplicity of infection). Additionally, maintaining the target cells in good growth condition is crucial to ensure normal transduction efficiency.

rAAV can package approximately 3.0 kb of genetic material. However, if you want to add a marker, such as GFP or RFP, the size of the gene that can be inserted will be smaller, around 1.5 kb.

Using your existing plasmid: The virus can be packaged and delivered in approximately 12–15 days.

Including plasmid construction: If we also need to construct the plasmid for your gene of interest, the full process typically takes 15–25 days, depending on the gene size, complexity, and any special design requirements.

Factors that can affect timing:

• Gene length (genes over 2 kb may require extra time)

• Sequence complexity or modifications

Additional quality control steps requested by the customer

（1）The most likely reason is: When lentivirus is used, an excessive viral dose can severely damage the cell genome and cell membrane. Therefore, it is necessary to determine the optimal MOI (multiplicity of infection) for each cell type, count the cells based on this value, and then use the appropriate lentiviral dose for the target cell infection.

（2）Other possible reasons: Lentiviral infection itself may induce cell differentiation, which affects the cell's proliferative ability.

（3）If the control lentiviral infection produces normal results but the target lentivirus shows abnormal results, it is possible that the gene targeted by the lentivirus is involved in processes such as the cell cycle, cell proliferation, cell metabolism, or cell adhesion. This situation is difficult to avoid but can generally be addressed by reducing the lentiviral dose, using an inducible expression system, or altering culture conditions.

（1）Functional effectiveness means: Validation is carried out on model cells (e.g., 293T, 3T3 cells) to confirm effectiveness.

（2）For overexpression and related lentiviruses, the expression of the promoter varies across different cell types. As a result, the same lentivirus infecting different cells may produce different effects.

（3）For RNA interference lentiviruses, the background expression levels of the target gene and the differences in the intracellular environment across different cell types may lead to different effects from the same lentivirus infecting different cells.

Our service provides high-titer, high-purity adenoviral vectors customized to your needs. Each delivery includes target and control viruses, precise titers, a detailed shipping list, and usage instructions for seamless integration into your experiments.

Adenovirus enables rapid, strong, and transient gene expression in a broad range of mammalian cells. It remains episomal without integrating into the host genome, supports large genes, and provides high transduction efficiency, making it ideal for in vitro and in vivo studies.

Viral Particles (VP) represent the total number of both live and dead viral particles and do not reflect the amount of active virus in the preparation. Plaque Forming Units (PFU) represent the number of infectious or live viruses, providing a measure of the active virus present. Infectious Units (IFU) are equivalent to PFU. For most virus preparations, the VP/PFU ratio is 20:1 to 50:1. Using VP as a measurement can result in significant variations in the amount of actual live viruses present, whereas using IFU or PFU gives more consistent outcomes.

Key indicators for assessing the quality of a mutation library include:

- Diversity of mutations: The mutations in the library should cover a wide range of variations in the target gene, ensuring sufficient representativeness.

- Complexity of the library: This refers to the number of mutant variants in the library, ensuring the library size is large enough to cover possible mutation combinations.

- Accuracy of mutations: The accuracy of mutations in the library should be verified using high-throughput sequencing techniques (such as NGS) to avoid the introduction of erroneous mutations.

- Consider the target cell type, as some cells are more sensitive than others.

- Higher titers aren't always better—too high can be toxic or trigger immune responses.

- Start with small-scale tests to determine the optimal functional titer.

- Use qPCR or Western blotting to check gene expression changes.

- Functional assays (like reporter assays or phenotypic readouts) can confirm the library's effect.

- Sequencing can confirm the guide RNA or mutation was correctly introduced.

Polyclonal stable cell line (cell pool): This is obtained by directly selecting cells with drug resistance after transfection. It consists of multiple clones from different sources, with varying integration sites and expression levels of the exogenous gene. It has a short production cycle and low cost, suitable for initial screening and high-expression applications.

Monoclonal stable cell line: This is derived from a cell pool through methods such as limiting dilution, and consists of a single clone of cells with stable integration of the exogenous fragment. All cells have the same integration site, ensuring consistency and stability in expression. It is suitable for high-precision research and biopharmaceutical production. However, it has a longer production cycle and higher cost, and is ideal for cell line experiments requiring subcellular localization, difficult-to-infect cells, and low-expression applications.

Each project includes comprehensive validation such as sequencing results, qPCR data, and optional protein-level verification (e.g., Western blot), ensuring reliable and reproducible results.

Overexpression cell lines are faster and more cost-effective to construct, and they are suitable for studying gene function at the protein level. However, expression may be non-physiological due to strong promoters or random genomic integration. Knock-in cell lines, on the other hand, place the gene under its natural promoter, allowing physiologically relevant expression and more accurate functional studies. The trade-off is that knock-in projects are more complex and typically require longer timelines.

Optimize elution conditions by gradually lowering the pH from a high value; neutralize the purified sample promptly, or even neutralize while purifying; prepare and store the sample at low temperatures during the purification process; add protein protectants such as glycerol and Tween; when antibody concentration is high, dilute in time to avoid the risk of aggregation due to high concentration.

The verification can be done from the following three aspects:

First, at the molecular sequence level, after constructing the expression vector, the expression plasmid is sequenced for confirmation. Sequencing files can be used for verification.

Second, during the expression process, a comparison is made between induced and uninduced lysis buffers. Differences in protein bands can be detected by SDS-PAGE. The difference can be observed at the theoretical size of the target protein.

Lastly, Western blot (WB) validation can be performed using tag antibodies or antibodies specific to the target protein.

If protein verification is needed, protein coverage analysis can be conducted by comparing the theoretical sequence with the actual coverage ratio. However, the purity of the target protein must be greater than 90%. If the purity is lower, the coverage ratio may be affected. For lower purity samples, gel slicing can be performed for further analysis.

The advantage of eukaryotic expression systems over prokaryotic systems is that the protein activity is generally better. In theory, most proteins expressed in eukaryotic systems are active. However, the stability of different samples may vary, so the actual experimental results should be used as the basis for determining protein stability.

Advantages of CHO Cells:

• Can grow stably in chemically defined, serum-free suspension cultures.

• Well-characterized genome and generally safe with respect to human pathogenic viruses.

• Capable of human-like post-translational modifications (e.g., glycosylation).

• Amenable to genetic modification and stable cell line generation.

Advantages of HEK293 Cells:

• Faster growth rate compared to many other mammalian lines.

• High cell density and very high transfection efficiency.

• Produce post-translational modifications that closely resemble human protein structures.

Clients need to provide the gene sequence. Once confirmed, our team will design the optimal expression strategy for your project.

Pricing depends on gene length and protein difficulty. For non-guaranteed expression services, if expression is unsuccessful, 50% of the cost may be charged. Guaranteed expression services ensure successful production. The default delivery is 1 mg, with larger amounts available upon inquiry.

Clients need to provide the peptide sequence(s). For modified or structured peptides, specify the modifications or structural type required.

Our services are designed for rapid turnaround: e.g. recombinant antibody production in 2–5 weeks, hybridoma sequencing in 1–2 weeks.

All antibodies undergo rigorous QC such as SDS-PAGE (>95%), HPLC purity checks, and endotoxin testing (<1 EU/mg). Sequencing services include raw data, sequence verification, and optional NGS validation.

Yes. We support full-length IgG, Fab, VHH, and polyclonal antibodies, across multiple species (mouse, rabbit, camelid). Clients can provide their own antigens or request custom antigen design and preparation.

To begin a project, clients need to provide the DNA sequence of the target protein. Any specific requirements regarding expression system, protein quantity, or purity can also be communicated to help design the optimal expression strategy. Additional services, such as endotoxin removal, protein purification, or QC options, can be requested based on the project needs.

Clients receive purified protein (with SDS-PAGE >85% purity), expression plasmids, optional expression strains, and a COA report. Additional QC options, such as SEC-HPLC, endotoxin testing, Western blot verification, and protein coverage analysis, are also available upon request.

For certain services, if protein expression fails, clients may be charged 50% of the project cost to cover the expenses already incurred. Guaranteed expression services include multiple strategies to ensure success, minimizing the risk of failure.

We can synthesize peptides up to 30 amino acids for standard orders, with scales ranging from 1 mg to 1 g for lab-scale projects, and up to 1 kg or more for large-scale/bulk synthesis.

Peptides can be provided at purity levels from 75% to 98%, allowing you to select the optimal balance between cost and experimental requirements.

Standard synthesis is optimized for peptides up to 30 amino acids. For longer sequences, complex modifications, or unusual amino acids, we recommend consulting with our team for customized solutions.

Depending on the service, some antibodies are provided as purified protein ready for use, while others, like plate supernatant antibodies, may require additional purification before sensitive applications.

The main differences are in quantity, turnaround time, and QC standards:

Standard Recombinant Antibody Expression: Designed for research-scale production (3 mL – >1 L). It has a fixed 2-week turnaround and high QC standards (SDS-PAGE >95%, HPLC >95%, Endotoxin <1 EU/mg). This service is ideal when the primary goal is rapid, small- to medium-scale antibody production.

Guaranteed Recombinant Antibody Expression: Provides a guaranteed yield (10–1000 mg) and a slightly longer turnaround (2–5 weeks). QC standards are also high (SDS-PAGE >95%, HPLC >90%, Endotoxin <1 EU/mg), but this service is specifically suitable when a precise amount of antibody is required for experiments or downstream applications.

Yes, we offer custom bispecific antibodies and tagged formats (e.g., VHH-His, VHH-Fc). Secondary purification can be requested to meet specific research requirements.

Customers should provide more than 1 × 10⁶ frozen hybridoma cells or Trizol-processed cells. Antibody subtype information and hybridoma species/source details are also needed.

The turnaround time is approximately 1–2 weeks, depending on the service type (variable region sequencing, full-length sequencing, or NGS high-throughput sequencing).

You will receive an electronic report containing the antibody light and heavy chain sequences, along with raw sequencing data (NGS in FASTQ format, no chromatogram files).

Our Antibody Screening Service covers monoclonal antibodies from single B cells (mouse and rabbit), as well as nanobodies from natural human or camelid libraries. Clients receive validated sequences and, where applicable, recombinant antibody proteins suitable for downstream research or therapeutic applications.

After supernatant screening, approximately 100 μL of culture supernatant from each positive clone is provided to the client for functional validation. Only the candidates that pass this validation proceed to antibody gene sequencing and recombinant expression.

Human antibody library: Derived from 100 donors, with a titer of 2×10¹³ PFU.

Camelid VHH (single-domain) library: Derived from 200 camels, with a titer of 2×10¹³ PFU.

Our Antibody Discovery service covers the full workflow from antigen design and synthesis, immunization, hybridoma or polyclonal screening, antibody purification, functional testing, and optional labeling or fragmentation. We provide high-affinity, validated antibodies ready for research or therapeutic applications.

The Rapid Rabbit service uses an optimized high-efficiency immunization system, reducing the immunization period to 4 weeks while still producing high-affinity, validated antibodies. This allows delivery of purified antibodies and functional data in just 7 weeks, compared to 9–11 weeks for standard polyclonal services, without compromising quality or specificity.

Yes! All antibodies are validated, and accompanied by ELISA or QC data, ensuring they are ready for research.