Lysing tissue-culture cells for immunoprecipitation

INTRODUCTIONFor cells grown in tissue culture, the most useful method of lysis is treating with detergents, as described in this protocol. Non-ionic detergents, such as NP-40, solubilize the plasma and intracellular membranes, break many weak intermolecular bonds, and solubilize most of the commonly studied protein antigens. RIPA lysis buffer, which contains non-ionic detergents mixed with ionic detergents, may be used as a more rigorous extraction buffer to release all but the insoluble proteins of the cell and to break most weak noncovalent interactions. The resulting lysate is ready for preclearing.