need help with gst-tagged protein-purification - (Jun/06/2012 )

hey guys!

i have a problem.

i expressed a protein in insect cells and now try to purify it. it is gst tagged and has a molecular weight of 120kDa.
everything works just fine but i am not able to elute the protein. if i check via westernblot it is still located on the glutathion-sepharose-beads.
i tried with an elution-buffer containing 40mM Glutathion.
do you have an advice for me?

thanks a lot!

try to modify the pH and ionic strenght in the elution buffer...