Dissolving cell pellet after sonication
Follow the instructions that came with your column for cleaning. The resin will probably be fine, but you'll need to thoroughly clean the column. My GE columns recommend washes of:


20% EtOH
30% Isopropanol
1M NaOH
1M NaCL
SDS in 0.1M Acetic Acid
Stripping buffer (EDTA)


Wash between each with several column volumes of distilled water. You may not need to do all of them. Then just recharge your column with a 100 mM Ni solution (or metal of choice)