Hi,

I am not an expert in this field. If an expert could help with the following that would be great.

Is there a lower concentration, one would expect streptavidin not being able to bind to biotin anymore? I have biotinilated oligos and have them at concetrations of say 0.1 nanomolar. If one mixes streptavidin into that (equimolar or more streptavidin even) would one expect the streptavidin be able to actually find the biotin or not?

Thanks a lot

Best wishes

Daniel

Biotin-Streptavidin binding is very, very tight (almost covalent ) so i would expect, that you definitly get binding

Although the binding is indeed tight, if the concentration is too low, the strepavidin may not be able to find the biotin. You can try adding excess streptavidin, or increasing the incubation time, or if this is being done on a column recirculating the oligo solution.