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Maximum gene silencing with siMAXTM small interfering RNA

siRNAs inhibit gene expression

siRNAs belong to a class of double-stranded RNA molecules. These short duplexes play an important role in the RNA interference (RNAi) pathway, where they interfere with the expression of specific genes with complementary nucleotide sequence.

siMAXTM siRNAs are purified, annealed, and ready-to-use: 

When you order a siMAXTM siRNAs from Eurofins Genomics, each duplex is provided after annealing the individually purifying the oligos using HPLC. The duplex is ready for resuspension and use. Ever siMAXTM siRNA is

  • Desalted and HPLC purified
  • Provided in 20 nmol or 40 nmol quantity
  • Guaranteed purity of 85% (HPLC purified)
  • Sequence lengths from 17–27 bases
  • Quality control by MALDI-TOF MS

A free 1 mL 5x siMAXTM dilution buffer (30 mM HEPES, 100 mM KCl, 1 mM MgCl2, pH 7.3) is included with each shipment.

All relevant documents are provided either online or printed:

  • Oligo synthesis report
  • Delivery note

siMAX siRNA Specifications

Effective silencing is most readily achieved through delivery of a guide strand with high fidelity to the siRNA and microRNA seed regions. To accelerate your research we have developed extensive quality control procedures to confirm the identity of each component of the siRNA duplex. Allow us to help you achieve the best in RNA silencing with the siMAXTM siRNA—a duplex containing RNAi sense strand (passenger strand) and the RNAi antisense strand (guide strand) with the highest quality.

Features of siMAXTM siRNA Details
Delivered yield 20 & 40 nmol
Available Modifications DNA bases, 2'-O-methyl and others
Available Oligo Lengths (in nt) 17–27 bases
Default Purification HPLC
Delivery Formats Dried duplex siRNA in tubes

Each siMAX siRNA duplex is provided as a quality-assured siRNA duplex with a purity level of 85% or greater. After passing all quality control tests, 20 nmoles (or 40 nmoles) of both the sense and antisense RNA oligos are placed into a tube, annealed, and then shipped as dried material to your lab.

You shouldn’t have to choose between the best reagents for your gene silencing experiments and the health of your lab budget. By providing the highest quality and excellent value, siMAXTM siRNA empowers every RNAi gene silencing experiment.

Accelerate your research with our “fully annealed” siMAX siRNA duplexes. Our protocol for resuspension of the dried duplex is designed to make sure that the oligos are reannealed just prior to use. You may use our siRNA Dilution Buffer (included free with each shipment along with resuspension instructions) or your own preferred buffer to prepare the siRNA duplex for further use.

Resuspending siMAXTM siRNA duplex

Avoid RNA degradation by using special precautions and by wearing protective lab clothing and gloves. All solutions should be qualified as RNAase-free and reserved only for use in RNA experiments. All RNA work spaces must be free of RNAase contamination. If you have any questions, please contact our Technical Support team at 800-688-2248.

  1. Add 1 mL of siRNA Dilution Buffer to the lyophilized siMAXTM siRNA to create a 20 µM stock solution. (siRNA Dilution Buffer, pH 8.0 is a TRIS-EDTA buffered solution for use and/or storage of siRNA.)
  2. Heat the tube to 90 °C for 60–90 seconds.
  3. Incubate at 37 °C for at least one hour.
  4. The siRNA duplex 20 µM Stock solution is now ready for use.

If you have any questions, please contact our Technical Support team toll-free at 800-688-2248.

Traditional methods for the design of siRNA for use in RNAi have recommended the use of 21-mer siRNA moelcules— comprising of a 19-mer duplex with, typically, dTdT overhangs. We have, however, offered the ability for you to choose from a range of overhangs through our siMAXTM siRNA order editor.



More recently longer RNA duplexes, 27-mers, that can act as substrates for the Dicer enzyme and generate the siRNA in vivo, have been found to be very effective at gene silencing. These dsiRNA molecules can also be chemically synthesized. The structure of these RNA duplexes is shown below.


siMAX siRNA Prices

The price of unmodified Sense and Anti-sense duplex where each strand is between 17 and 27 bases long.

Purified siMAX siRNA (≥90% purity)
20 nmol (delivered quantity) $ 220.00
40 nmol (delivered quantity) $ 275.00

Modified bases or linker can also be included 5'- and/or 3'-termini of the individual oligos in the siMAXTM siRNA duplexes. Available modifications and the price of inclusion per oligo is included below.

5' Modification 20 nmole 40 nmole
2'-OMe Base $ 15.00 $20.00
5 HEX $ 125.00 --
6 FAM $ 125.00 --
6 TET $ 125.00 --
Amino C6 $ 25.00 $40.00
Biotin TEG $ 100.00 --
Chol TEG $ 225.00 --
Cyanine 3 $ 140.00 --
Cyanine 5 $ 140.00 --
Phos $ 30.00 $ 45.00
3' Modification 20 nmole 40 nmole
6 FAM $ 125.00 --
Amino C7 $ 25.00 $ 40.00
Biotin TEG $ 100.00 --

Related Links

Scale and Yield Guaranteed yields for unmodified oligos at different scales. NOTE: Plate-format oligos are available in the 10 nmol, 25 nmol, 50 nmol, and 0.2 μmol scales. These oligos are delivered in 96-well plates and concentration normalized at 50 µM in 200 µL or delivered after drying the same down. Place orders for up to 1000 plate-format oligos online or email your order for more than 1000 oligos contact