siRNA

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Overview

RNA interference (RNAi) is a phenomenon that inhibits the expression of specific genes in organisms. When double-stranded RNA (dsRNA) homologous to the endogenous mRNA coding region is introduced into the cell, it triggers the degradation of the target mRNA, leading to gene silencing.

 

After the exogenous dsRNA enters the cell, it generates small interfering RNAs (siRNAs). Small interfering RNAs (siRNAs) are double-stranded RNA molecules typically 21-23 nucleotides in length (19-25 nucleotides is acceptable according to the literature). These siRNAs usually have two nucleotide overhangs at the 3' ends. The antisense strand of these siRNAs, along with various nucleases, forms the RNA-induced silencing complex (RISC), which has the ability to bind to and cleave mRNA, thereby mediating the RNA interference process.

 

Tsingke has a complete oligonucleotide synthesis platform and can provide customers with conventional siRNA and various modified siRNA synthesis services, ranging from microgram to kilogram quantities. The company strictly adheres to ISO 13485:2016 quality control standards and ensures the delivery of high-quality siRNA to customers through multiple quality control methods, such as ESI mass spectrometry and HPLC purity testing.

Advantages
High Quality
 Oligos available from RUO to GMP compliance


Comprehensive modifications
Achieving a high modification rate and incorporating stable groups such as PS, 2’-F, 2’-OMe, and FAM to ensure suitability for downstream applications
Expertise
We synthesize over 120,000 oligos annually



Cost-effective solution
Leverage Tsingke's whole  industry chain advantages
High Purity
HPLC purity detection ensures purity levels greater than 90%


Customization
Multi-channel synthesizer with μg to kg level synthesis. 
Service Details

Service

Details

lengthnt)

Quantity

Turnaround Time

(Business Day)

Purification

QC

Deliverable

siRNA

 Custom synthesis

20-25

5 nmol or 2 OD

3-4

RNase free HPLC

HPLC

· Tube or customized 
lyophilized RNA

· COA report

 (electronic)

siRNA NC

Various types available: negative/positive control siRNA, transfection control siRNA, etc.

In-stock

3 siRNA,

1 Guaranteed

With a transfection efficiency of 80%, at least one out of the three siRNAs should achieve an mRNA interference efficiency of over 70%.

5 nmol or 2 OD

3-4

HPLC

4 siRNA,

1 Guaranteed

With a transfection efficiency of 80%, at least one out of the four siRNAs should achieve an mRNA interference efficiency of over 70%.

5 nmol or 2 OD

3-4

Large-scale

siRNA

Up to kg level gmp

≥20 nmol or 

Evaluation

Workflow
High-throughput synthesizer from pmol to mmol levels
Synthesis
High-throughput synthesizer from pmol to mmol levels
RNase free HPLC
Purification
RNase free HPLC
MS (HPLC/SEC-HPLC - Optional)
QC
MS (HPLC/SEC-HPLC - Optional)
Automatic dispensing instrument for accurate dispensing
Distribution
Automatic dispensing instrument for accurate dispensing
Tube or Customized、Lyophilized RNA、COA Report
Delivery
Tube or Customized、Lyophilized RNA、COA Report
Case
MS
siRNA transfected MRC-5 cells and interfered with CD44
Transfected siRNA into HEK-293 cells to induce interference with


FAQ
What do I need to provide for PCR cloning services?
a.Templates:  Provide and send us the template plasmid. 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 160+ 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 site information.
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 gene@tsingke.com.cn to place your order. the 
a.Templates:  Provide and send us the template plasmid. 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 160+ 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 site information.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 gene@tsingke.com.cn to place your order.
Why is no fluorescence observed after transfection?
 Usually, FAM shows green fluorescence (excitation wavelength 495 nm) and CY3 shows red fluorescence (excitation wavelength 550 nm) after transfection. If no fluorescence is observed, consider the following:**
1.Is the fluorescence excitation wavelength correct?
  - Ensure that the excitation wavelengths are set to 495 nm for FAM (green) and 550 nm for CY3 (red).
2. Were the cells washed immediately after transfection?
   - Wash the cells immediately after transfection to observe fluorescence. Delaying this step can result in reduced fluorescence.
3. Was the siRNA product stored properly?
   - Improper storage can lead to siRNA degradation and FAM fluorescence quenching. FAM is particularly sensitive to light, so store it away from light.
4. Was the transfection performed away from light?
   - Operate away from light during transfection. Avoid exposing FAM to white light for extended periods.
5. Was fresh medium replaced in time after transfection?
   - Prolonged transfection times without timely replacement of fresh medium can affect fluorescence. Ensure fresh medium is added promptly post-transfection.
Why is there a lot of cell death after transfection?
Poor cell health before transfection can lead to increased cell death. Ensure cells are in optimal growth condition, as healthy cells better tolerate transfection reagents. High concentrations of siRNA or transfection reagents can be cytotoxic, so adjusting these concentrations may be necessary. Some transfection reagents are more toxic; consider switching to a less toxic alternative. Low-purity siRNA may contain impurities that affect cell viability; therefore, using high-purity siRNA is recommended. Additionally, prolonged transfection times can exacerbate cell death; ensure timely replacement of fresh medium after transfection.
Why is there low efficiency of cell transfection?
Low efficiency of cell transfection can occur due to several reasons:
Insufficient siRNA purity may lead to RNA enzyme contamination. Use DEPC-treated consumables and reagents to prevent this issue.
Adjusting the concentration of the siRNA-transfection reagent complex can enhance transfection efficiency.
Serum in the transfection mixture can interfere with efficiency. Prepare the mixture without serum to minimize this effect.
Avoiding antibiotics in the culture medium is recommended as they can inhibit transfection efficiency.
How long does siRNA work within cells? When is the best time to perform detection?
siRNA-mediated RNA interference (RNAi) is a transient phenomenon and cannot be stably propagated through cell generations. Its effects typically do not last for an extended period, and it is generally recommended to complete detection within 3-4 days post-transfection. The optimal detection time varies depending on the cell type and target gene, but it is usually between 24-48 hours post-transfection. It is generally suggested to assess mRNA levels at 24-48 hours and protein levels at 48-72 hours post-transfection.
Is transfection efficiency related to the siRNA sequence?
Transfection efficiency depends on the characteristics of the cells and the transfection method used, and it is not directly related to the siRNA sequence. Therefore, siRNA transfection efficiency may vary across different cell types.
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