Lysostaphin, an endopeptidase specific for the cell wall peptidoglycan of staphylococci, is an extremely potent anti-staphylococcal agent. Lysostaphin is used as a research and diagnostic tool. Because it lyses staphylococci efficiently, it is widely used when preparing staphylococcal DNA or other cellular components for genetic and biochemical studies and for the preparation of protoplasts for transformation. Preparation and analysis of bacterial DNA has become a powerful tool used by clinical and other microbiologists in epidemiological studies aimed at tracing sources of infection or bacterial contamination.The Mw of lysostaphin is 26,921 (Recsei et al, PNAS 1987).Lysostaphin has optimal stability in the range of pH 4.5, and optimal activity in the range of pH 8. For a stock solution it is recommended to work with 10mg/ml lysostaphin in 10mM sodium acetate pH 4.5. For a reaction buffer it is recommended to work with 200mM Tris-HCl pH 8.