Conditions are described for the separation of synthetic oligodeoxyrib
onucleoside phosphorothioates by HPLC using a SCOUT WP PEI weak anion
exchanger and for the separation of oligodeoxyribonucleotides with mix
ed phosphate and phosphorothioate internucleotide bonds on a Partisphe
re C-18 support in ion-pair conditions. The influence of the nucleosid
e composition and the number of phosphorothioate bonds on the retentio
n time was studied.