Chemically-Modified siRNA

Chemically-Modified siRNA

siRNA is one of the valued tools which is widely used to investigate the functions of genes and gene silencing. However, poor stability, immunogenic and off-target effects make siRNA is not optimal drug-like molecule. Chemically-modified siRNA overcomes these challenges, chemical modifications of siRNA therapeutics significantly improve their pharmacological and therapeutic properties.

There are three kinds of chemical modifications

Ribose modification

Ribose modification can strongly influence sugar conformation as it allows the oligonucleotide to adopt the energetically favorable conformation, therefore, formation of thermally stable A-type duplexes was expected upon the introduction of these modifications into siRNAs. And ribose modifications can also improve endonuclease resistance.

Examples: 2′-O-Me, 2′-O-methoxyethyl (2′-O-MOE), 2 -O-allyl, 2 -O-cyanoethyl), 2 -O-ethylamine, 2 -O-DNP, 2 F-RNA, 2 F-ANA, 4 S-RNA and 4 S-2 F-ANA).

Phosphate backbone modification

Chemical modifications to the phosphate backbone are tolerated by RNAi. Internucleotide linkages used in siRNA will retain the negative charge of a phosphate and can be cleaved by endo and exonucleases.

Examples: phosphorothioate linkage, boranophosphate linkage, phosphonoacetate linkage.

Base modification

The use of base modification is more limited than other kinds of chemical modifications, but there are still many applications. Some modified bases can stabilize AU base pairs and increase the strength of AU base pairs.

Examples: 5-halouracils, 2- thiouracil, pseudouracil, diaminopurine.

BOC RNA provides high-quality and cost-effective siRNA with various chemical modifications and flexible synthesis scales to meet customers' needs.

All our chemically-modified siRNAs are purified by HPLC, and supplied in lyophilized powder. The quantity we can provide ranges from 2 OD to 250 OD.

Cat No.ModificationQuantityPurificationPriceLead Time
BRD-001Deoxyinosine2 OD-250 ODHPLCInquiryInquiry
BRD-0022'-Fluoro-rU2 OD-250 ODHPLCInquiryInquiry
BRD-0032'-Fluoro-rC2 OD-250 ODHPLCInquiryInquiry
BRD-0045'-Bromo-rU2 OD-250 ODHPLCInquiryInquiry
BRD-0052'-OMe-rU2 OD-250 ODHPLCInquiryInquiry
BRD-0062'-OMe-rC2 OD-250 ODHPLCInquiryInquiry
BRD-0072'-OMe-rG2 OD-250 ODHPLCInquiryInquiry
BRD-0082'-OMe-rA2 OD-250 ODHPLCInquiryInquiry
BRD-0095'-Phosphate2 OD-250 ODHPLCInquiryInquiry
BRD-0103'-Phosphate2 OD-250 ODHPLCInquiryInquiry
BRD-0115'-Amine2 OD-250 ODHPLCInquiryInquiry
BRD-0123'-Amine2 OD-250 ODHPLCInquiryInquiry
BRD-0135'-Biotin2 OD-250 ODHPLCInquiryInquiry
BRD-0143'-Biotin2 OD-250 ODHPLCInquiryInquiry
BRD-0155'-Thiol2 OD-250 ODHPLCInquiryInquiry
BRD-0163'-Thiol2 OD-250 ODHPLCInquiryInquiry
BRD-0175'-Digoxin2 OD-250 ODHPLCInquiryInquiry
BRD-0183'-Digoxin2 OD-250 ODHPLCInquiryInquiry
BRD-019Spacer C32 OD-250 ODHPLCInquiryInquiry
BRD-020Spacer C62 OD-250 ODHPLCInquiryInquiry
BRD-021Spacer 92 OD-250 ODHPLCInquiryInquiry
BRD-022Spacer 182 OD-250 ODHPLCInquiryInquiry
BRD-0235'-Cholesterol2 OD-250 ODHPLCInquiryInquiry
BRD-0245'-Ferrocene2 OD-250 ODHPLCInquiryInquiry
BRD-0253'-Ferrocene2 OD-250 ODHPLCInquiryInquiry
BRD-0262'-Isoproply2 OD-250 ODHPLCInquiryInquiry
BRD-027phosphorothioates2 OD-250 ODHPLCInquiryInquiry

Please send email to if you need other modifications.

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Ref:

  1. WATTS, J., DELEAVEY, G., & DAMHA, M. (2008). Chemically modified siRNA: tools and applications. Drug Discovery Today, 13(19-20), 842–855.
  2. Selvam, C., Mutisya, D., Prakash, S., Ranganna, K., & Thilagavathi, R. (2017). Therapeutic potential of chemically modified siRNA: Recent trends. Chemical Biology & Drug Design, 90(5), 665–678.
  3. Deleavey, G. F., Watts, J. K., & Damha, M. J. (2009). Chemical Modification of siRNA. Current Protocols in Nucleic Acid Chemistry, 16.3.1–16.3.22.

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