Calf intestinal alkaline phosphatase (CIAP) catalyzes the hydrolysis of 5'-phosphate termini from DNA, RNA, dNTPs and rNTPs. This enzyme can be used to reduce linear vector self-ligation and vector background during cloning. CIAP is supplied in a buffer of 10 mM Tris-HCl (pH 8.0), 50 mM KCl, 1 mM MgCl2, 0.1 mM ZnCl2, and 50% glycerol.