Gel filtration estimations - (Oct/09/2006 )

I can't find any manuals on gel filtration type columns here or my searches so far. I am trying to figure what is the best size column (and type - currently trying G-50 and G-75 ~100um) for separating an approximately 20kDa protein from an approximately 55kDa protein.

I was hoping there would be some theoretical calculations to estimate approximate elution patterns/times on the different size columns for different size proteins. Does anyone know a good website or book that might be relavant? I've checked biochem texts and tried some web searches with not much luck yet... is it all just trial and error? If so, any ideas on similar sized proteins you may have done before (I'm also trying to find any papers that may have purified similar proteins by gel filtration, not too much luck so far in getting any good details)?

Thanks a lot.

Try Sepahacryl S100 or S300 for mannul columns, and superdex for FPLC settings. For Sephacryl resins, 50-60 cm column highth is typical. Your sample volume determines what diameter of column to use. Pharmacia has some useful downloads for these applications.