A chromatographically purified, diafiltered, lyophilized powder that has been treated with L-(tosylamido-2-phenyl) ethyl chloromethyl ketone (TPCK) to inhibit contaminating chymotryptic activity [Kostka, V., and Carpenter, F.: JBC, 239, 1799 (1964)]. Store at 2-8C. Protect from moisture.
