Backbone modification: Phosphorothioates (PTOs)
For antisense applications, we offer the nuclease-resistant Phosphorothioates.
Introduced at either the 5'- or 3'-end of an oligo phosphorothioates can inhibit exonuclease degradation. If they are introduced internally, they can limit attacks by endonucleases.
Non-specific protein binding can be increased by phosphorothioates, however this can cause toxicity or other artifacts when present at high concentrations. To reduce or even eliminate such problems, chimeric oligos can be used.