Thiophosphoramidites are reagents used to synthesize internucleotide linkages that contain two non-bridging sulfurs in place of the oxygens. These PS2 linkages when used in aptamers can result in significantly increased binding affinity and much slower off-rates (See Improve Existing Aptamers & siRNA). When used in siRNA, PS2 linkages can result in increased gene silencing.

AM Biotech sells thiophosphoramidites in 1g, 2g, 5g, 10g, and 20g packages.

IMPORTANT: thiophosphoramidites required non-standard synthesis protocols for best results.

DNA Thiophosphoramidite Synthesis Protocol

RNA Thiophosphoramidite Synthesis Protocol

2’-OMe Thiophosphoramidite Synthesis Protocol