Custom siRNA synthesis

The most widely used siRNA are 21-mer. They are usually composed of 19 double stranded RNA bases and 2 single stranded DNA bases (usually two Thymidine) in 3’end. We offer multiple options available to synthesize the siRNA molecule that fits at best your need.

The standard specifications displayed here can be adapted according to your application. If you need assistance, we offer free siRNA design with a silencing guarantee.

Configure your siRNA

siRNA Specifications

siRNA sequence length is comprised between 21 and 27 bases

We manufacture siRNA in small and large quantities.

  • SePOP purified siRNA are delivered in 7, 22, 60 or 200 nmol
  • HPLC and in vivo purified oligos are delivered in 3, 12, 40 or 80 nmol

Larger scales are available on request.

siRNA sequences can be built with RNA, LNA®, 2’O-Me RNA
or 2'O-MOE RNA bases.

Phosphorothioate linkages can be added to increase
nuclease resistance.

We can modify your siRNA sequence with various molecules :

  • 5’ modifications : Phosphate, 6-FAM, AlexaFluor®, ATTO, Biotin, Cy®3,
    Cy5®, Fluorescein, HEX,...
  • 3’ modifications : 6-FAM, Cy®3, Cy5®, Rhodamine, TEG-Cholesteryl, TAMRA...

siRNA oligonucleotides can be purified by IEX-HPLC or RP-HPLC
or follow our SePOP Desalting or in vivo process

We control every production of custom siRNA oligonucleotides

We deliver custom siRNA sequence dried at room temperature in 2 mL tube

A purity adapted to your application

We manufacture and deliver your siRNA oligonucleotides to reach the purity level your application requires.

SePOP Desalted IEX/RP-HPLC In Vivo*
Desalting by precipitation
Desalting by size exclusion chromatography
Sterile filtration  

Comparison between the SePOP and HPLC purifications and the in vivo process method for a siRNA duplex

*Production process endotoxin tested

The interest of siRNA duplexes

RNA oligonucleotides are mainly used to study the involvement of RNA in gene regulation. Synthetic siRNA duplexes are introduced into cells to cause RNA interference and inhibit the expression of a specific messenger RNA (mRNA).

Figure 1 : 

Principle of siRNA-mediated RNA interference. The annealed siRNA enters the cell (1). Once inside, double stranded RNA is recognized by the RISC complex. Sense strand siRNA is displaced and the mRNA anneal to the antisense siRNA fixed to the RISC complex (2). mRNA is digested (3) and the RISC complex containing the siRNA is then recycled to begin a new cycle (4).

Control siRNA