problem purifying a his-tag protein - (Dec/15/2005 )
Ihave been trying to purify a his-tag protein without success. i have used gel filtration, qiagen spin column and batch protocols and none of them has worked, yet i know that the expreesion worked well coz i run sds-page and confirmed it. please help.
Sure you don't have a stop codon between your protein and the tag? Check the sequencing. Or try a western blot of lysate using anti-his.
have you been to Qiagen's website and checked out the troubleshooting for solubility issues? if you see good induction but can't get the column part to work, I would bet it's a solubility issue (assuming all your buffers are good)