Streptavidin on to CM5 chip

Does anyone know if you get better results using the SA chips, or with using the CM5 chips and amine coupling the strep on to it? Is there a protocol that people have tried for this, as the one mentioned on the SA page doesn't seem to work for me www.sprpages.nl/sensor-chips-intro/biacore-sensor-chips/sa.html ? I get quite low immobilisation level (~200RU) and when i go on to immobilise/bind my biotinylated protein to the streptavidin, I get no further change in RU (the protein is confirmed to be biotinylated via MS.). Not sure if i'm doing something wrong. the way i see it, either the initial amine coupling of the strep didn't work properly, or the biotin (on a ~23 residue linker followed by the remaining protein) is blocked/buried.

Thanks.

Hi

Never tried it myself but had nice results with the SA-sensor chip.
You may also look in to the Biotin CAPture-sensor chip system. This is a regenerable SA-biotin sensor chip.
I had nice results with it. Look at www.biacore.com/lifesciences/products/Co...Pture_kit/index.html
It looks more expensive but you can use it several times to capture different biotinylated proteins.

Arnoud

In the past, i've known people to have very good results with doing fragment screening using biotinylated proteins and the SA-chip. I've never done the amine coupling of strep to a CM5 chip before, and am only doing it now simply for cost reasons (as the CM5 chip can be used for other things, the SA-chip is restricted for use only with biotinylated proteins which not many people in the lab use).