Effect of lysostaphin treatment on CL extraction efficiency. Prior to lipid extraction, cells (N315) were incubated for 3 min at 37°C in the presence of lysostaphin at the indicated concentrations. CL: Cardiolipin. PG: Phosphatidylglycerol. LPG: Lysyl-phosphatidylglycerol. The means and standard deviations of relative signal intensities are shown at the bottom.