siRNA Synthesis

siRNA synthesis has been internationally recognized as one of the most effective ways for silencing of target genes by body or body cells, and is widely accepted due to its low cost and high transfection efficiency.

The well-known siRNA synthesis is not only the optimum method for RNAi‐based clinical treatment, but also irreplaceable in drug development.

In collaboration with Cohesion Biosciences
(, Bio Basic Asia Pacific now provides two types of siRNA products, which are standard siRNA and chemically-modified siRNA, with various modifications of siRNA available in accordance to customer’s requirements.

1. Standard siRNA product

The single/unpaired strands in standard siRNA products provided by us have been completely removed via HPLC method. They can be used directly in experiments after dilution with the provided buffer. The standard siRNA products directly target the interested mRNA; therefore, it is recommended to detect the target mRNA expression level by real-time PCR to ensure the effectiveness of siRNA products.

2. Chemically modified siRNA

Bio Basic Asia Pacific provides a wide variety of chemically modified siRNA products, which include 2’-hydroxymethylation modification, Phosphorothioate modification, Fluoro modification, and so on. Our production team, who owns the advanced technology for siRNA synthesis, has addressed the concern of siRNA stability in transfection experiments via chemical modification.

To enhance the siRNA stability, the four ends of the double stranded siRNA were labeled with fluorescent markers. As compared to unlabeled siRNA, the labeled siRNA shows the advantage of high visibility during transfection process. The labeled siRNA can be easily observed by using flow cytometry, fluorescence microscope, laser confocal microscope and so on. This leading technology is advantageous as it is not only to optimize the transfection conditions and intracellular localization of siRNA, but also trace and analyze the relationship between transfection efficiency and protein expression during the whole transfection process.

Comparison Between Standard siRNA and Chemically-modified siRNA

Critical Challenge Standard siRNA Chemically-modified siRNA
siRNA degradation The non-modified standard siRNA is easy to be deGraded in cell culture process. Although it is effective in most in vitro experiments, its life expectancy is shorter in cell culture. The chemically-modified siRNA not only increases its life expectancy in serum and cell culture, but also strengthens its in vitro application capability.
Long time effect Relative short time effect, under normal circumstances for approximately one week. The chemically-modified siRNA has long time effect, its effective time is twice as that of the standard siRNA.
In vivo activity The standard siRNA has poor stability, usually is not applicable to in vivo experiments. The chemically-modified siRNA has strong stability in vivo.

Order information

Standard siRNA products

Product Final Yield Purification Method
Standard siRNA 2 OD HPLC

Lead Time (Business Day): 6 ~ 10 working days
Price (SGD): Pricing may vary subject to desired final yield and purification method.

Chemically-modified siRNA products

Terminal modification Final Yield Purification Method
5′ FAM 5 OD – 250 OD HPLC
5′ Biotin 5 OD – 250 OD HPLC
5′ Amine 5 OD – 250 OD HPLC
5′ Phosphate 5 OD – 250 OD
5′ Thiol 5 OD – 250 OD HPLC
5′ Cholesterol 5 OD – 250 OD HPLC
Base Modification Final Yield Purification Method
2′ Fluoro dU 5 OD – 250 OD HPLC
2′ Fluoro dC 5 OD – 250 OD HPLC
2′ OMe rU 5 OD – 250 OD HPLC
2′ OMe rC 5 OD – 250 OD HPLC
2′ OMe rG 5 OD – 250 OD HPLC
2′ OMe rA 5 OD – 250 OD HPLC

Lead Time (Business Day): 7 ~ 20 business days (subject desired final yield)
Price (Modification Cost + Synthesis Cost) (SGD): Please contact our local sales team for further details.

* Remark: For exact pricing, please contact our local technical support assistance team and indicate your desired scale and purification of the final product.

For order placing, please fill in the order form and provide us the following information: Click Here

  • Gene sequence/ GeneID or Accession Number
  • Sequence sense (5′-3′)
  • Sequence antisense (5′-3′)
  • Chemical Modification (if any)
  • Fluorescent Label (if any)
  • Special Modifications (if any)
  • Quantity (OD/nmol)

Upon the completion of project, we will provide:

  • siRNA products in customer’s desired scale and purification
  • Delivery reports that contain the siRNA oligo name and sequence; concentration; the precise number of OD and nmols; Tm; MW; Size; extinction coefficient and purification type.

Storage and Stability

Although oligonucleotides are stable in solution at 4°C for up to 2 weeks, recommends storage should be at -20°C. Repetitive freeze-thaw cycles should be avoided by storing as aliquots. Storing at concentrations above 20 uM is recommended. We guarantee the quality of oligonucleotides for 6 months upon receipt, provided that they are stored under the above conditions.

For further technical support assistance or other enquiries, please contact our local sales team:

Tel: +65 6928 9042