Bio-Synthesis provide phosphorothioate DNA oligonucleotide synthesis by substitute a sulfur atom for a non-bridging oxygen in the phosphate backbone of an oligonucleotide. While the natural phosphodiester bonds are highly susceptible to rapid degradation by cellular nucleases, the modification of internucleotide linkage using phosphorothioate (PS) bond substitutes can protect oligonucleoitdes from nuclease degradation and prolonged it's lifetime in serum which is an important characteristic for antisense and RNAi applications. However one drawback of this modification is that it does destabilize duplexes, redcuing the Tm by 1-3° C per addition. This can be minimized by the use of BNA oligonucleotides.  Phosphorothioate modified RNA are compatible with molecular biology experiment. 

Phosphorothioate DNA synthesized by Bio-Synthesis can be combined with other bases and/or sugar modified. These S-oigo  can be specified to have fully sulfur linkage substituted or a mixture of diester and thioate linkages as specified by customer. Contact us for phosphorothioate DNA synthesis.

Product Information


Product Name:

Phosphorothioate DNA Synthesis


Backbone Modifications, Antisense, Nuclease Resistance

Modification Code:

*dA, *dG, *dC, *dT


Bio-Synthesis Inc. Oligo Structure



Delivery Format:


Shipping Conditions:

Room Temperature

Storage Conditions:

-20°C To -70°C
Oligonucleotides are stable in solution at 4°C for up to 2 weeks. Properly reconstituted material stored at -20°C should be stable for at least 6 months. Dried DNA (when kept at -20°C) in a nuclease-free environment should be stable for years.