Replacing two non-bridging oxygen atoms with sulphur atoms in an oligo phosphodiester linkage creates a phosphorodithioate (PS2) linkage.⁽¹⁾ Like natural DNA, the phosphorodithioate linkage is achiral at phosphorus. This analogue is completely resistant to nuclease degradation and forms complexes with DNA and RNA with partially reduced stabilities.⁽²⁾ It has also been found that PS2-ODNs bind proteins with a higher affinity than their phosphodiester analogues suggesting that PS2-ODNs may have additional utility in the form of sulphur-modified phosphate ester aptamers (thioaptamers) for therapeutic and diagnostic applications. ⁽³⁾

We offer both DNA and 2’-OMe-RNA variant thiophosphoramidites.

Ref:

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