Phosphoramidite used to incorporate a dG nucleobase when creating phosphorodithioate (PS2) linkages.
LGC, Biosearch Technologies offers a wide range of high-quality amidites and reagents for modifying oligo backbones—all available in popular pack sizes and packaging formats, and most are available in bulk quantities.
Nucleoside phosphate backbone modifications are useful for increasing the stability of oligonucleotides duplexes and expanding the library of potential conjugates. Many oligo backbone modifications create unique binding capabilities and bolster sequence discrimination, making them useful for a variety of diagnostic and therapeutic applications such as SNP genotyping, antisense oligonucleotides, siRNA, and cell delivery.
We are constantly growing our portfolio of amidites and solid supports for incorporating oligo backbone modifications, and we listen to what our customers need. We now offer several locked nucleic acid (LNA) phosphoramidites and CPGs, as well as methyl and ethyl phosphoramidites.
Oligo backbone modification categories
|Peptide nucleic acids (PNA)
Generate oligos with a neutral backbone that assists in binding DNA, RNA and double-stranded DNA. Synthesis resembles peptide synthesis.
|Locked nucleic acids (LNA)
Synthesise oligos that strongly and specifically bind to DNA, RNA and double-stranded DNA. LNA oligos are synthesised using conventional phosphoramidite chemistry.
|Sulphurising reagent (EDITH)
Enable efficient and site-specific sulphurisation. This reagent is soluble in acetonitrile and stable in solution for several months.
Within one reaction the backbone of the entire oligonucleotide is converted to the required form (e.g., thiophosphate-sugar backbone).
Generate uncharged and nuclease-resistant oligonucleotide linkages— particularly useful for targeted cellular delivery of antisense therapeutic agents.
|Methyl or ethyl phosphoramidites
Improve cell delivery with our expanded offering of methyl phosphoramidites.
Replace non-bridging oxygen atoms with sulphur atoms to facilitate the attachment of site-specific reporter groups onto the DNA or RNA backbone or to create thioaptamers.
Properties of modified oligonucleotides
|Chemistry||Increased affinity||RNase H activity||Nuclease resistance|
|LNA||Yes||Yes (as chimera)||Yes|
Examples of suitable applications for different backbone modifications
|Methyl or ethyl phosphoramidites||
|Locked nucleic acids (LNA)||
|Peptide nucleic acids (PNA)||