Analysis Note Typical vial content: approx. 10 mg total protein (biuret)
Unit Definition One unit will hydrolyze 1.0 μmole of indicated substrate per min at pH 7.0 at 25 °C. Sold as benzylpenicillin units. This International Unit (using benzylpenicillin as substrate) is approximately equal to 600 Levy or 75 Pollock units.
Physical form Crude, lyophilized powder containing buffer and zinc salts, and stabilized with bovine serum albumin