Recommended for use with tissue and cell extracts including extracts containing detergents. A cocktail of five phosphatase inhibitors which has been optimized for the inhibition of protein tyrosine phosphatases, acid and alkaline phosphatases. Each vial contains 200 mM imidazole, 100 mM sodium fluoride, 115 mM sodium molybdate, 100 mM sodium orthovanadate and 400 mM sodium tartrate dihydrate.