Glen Research is delighted to introduce a GalNAc modification strategy using a monomeric GalNAc support and the equivalent GalNAc phosphoramidite. Our experimental work has shown that these products are fully compatible with regular oligonucleotide synthesis and deprotection. Oligonucleotides containing GalNAc can be deprotected using standard procedures during which the acetyl protecting groups on the GalNAc group are removed. Glen Research offers these GalNAc C3 products under an agreement with AM Chemicals LLC.
The most common usage for oligonucleotide phosphorothioates has been in the production of antisense oligodeoxynucleotides destined for use in identifying or modifying gene expression. Now, phosphorothioate linkages are popping up in the RNA world and sulfurizing RNA linkages with reagents like Beaucage Reagent has proved to be much more difficult than DNA linkages. The phosphorothioate (PS) linkage is a not-so-expensive way of increasing the stability of nucleic acids and increasing nuclease resistance of RNA. Now, it has been shown2 that fully PS oligos can promote the delivery of siRNA in cell culture. This siRNA uptake is sequence-independent and the length seems to vary between 30 and 70 nucleotides depending on the cell line. Even though this method is not yet as efficient as the cationic lipids, it opens the way to possible new methods. Reasons that may explain this are not understood at this time.
Oligonucleotide synthesis - Wikipedia
Detection of DNA damage: effect of thymidine glycol residues on the thermodynamic, substrate and interfacial acoustic properties of oligonucleotide duplexes.
Oligonucleotide Synthesis Market Size, Share, …
Another paper3 describes a method for the inactivation of micro RNA (miRNA) that may help to elucidate their functions. It uses 2’-OMe-RNA oligonucleotides (23-mers, complementary to a target miRNA) with a cholesteryl group at the 3´terminus and phosphorothioates at positions 1 and 2 at the 5´end and at the last four positions at the 3´end. These oligos are called antagomirs. These molecules promote the cleavage of complementary miRNAs and thus should allow analysis of their function. The role of the PS linkages presumably is the stabilization against degradation in the mouse experiments as it is standard in the antisense field in such in vivo situations. And finally, a recent paper4 shows that PS does not systematically abolish siRNA activity, opening the way for some potentially less expensive stabilization of such molecules. Incorporation of 2’-OMe (in the sense strand) in combination with PS linkages should confer to siRNA increased resistance to degradation by nucleases, as well as prolonged serum retention. And it is also possible that such easy modification of siRNA may increase the specificity by eliminating sense strand recruitment in the RISC complex and thus reducing a source of off-target effect.
RNA oligonucleotide synthesis - ATDBio
In this article, we introduce 5'-CDPI3 MGB™ Phosphoramidite and 3'-CDPI3 MGB™ CPG. Specific instructions are provided for the use of these products and the procedures are illustrated using HPLC and MS data. Details of a melting study using a CDPI3 MGB-oligonucleotide conjugate are presented.
custom oligo synthesis, oligonucleotides ..
This article by Eugene Lukhtanov of ELITechGroup Molecular Diagnostics introduces the tripeptide of dihydropyrroloindole-carboxylate (CDPI3), which is a minor groove binding (MGB) moiety derived from the natural product CC-1065 and exhibits strong DNA binding properties. Synthetic oligonucleotides with covalently-attached CDPI3 moieties have enhanced DNA affinity and have improved the hybridization properties of sequence-specific DNA probes. Short CDPI3-oligonucleotides hybridize with single-stranded DNA to give more stable DNA duplexes than unmodified oligonucleotides of similar length. The author describes the general properties of CDPI3 MGB-oligonucleotide conjugates in detail, along with some specific applications: