Shrimp alkaline phosphatase (SAP) nonspecifically catalyzes the dephosphorylation of 5'-termini DNA and RNA phosphomonoesters, but does not degrade diphosphate or triphosphate linkages. The enzyme acts on 5' protruding, recessive, and blunt 5'-termini. Unlike Calf intestinal alkaline phosphatase, SAP is irreversibly heat inactivated at 65°C for 15 minutes, allowing for streamlining of cloning experiments.