Calf-intestinal alkaline phosphatase
Calf-intestinal alkaline phosphatase (CIAP/CIP) is a type of alkaline phosphatase that catalyzes the removal of phosphate groups from the 5' end of DNA strands and phosphomonoesters from RNA. This enzyme is frequently used in DNA sub-cloning, as DNA fragments that lack the 5' phosphate groups cannot ligate. This prevents recircularization of the linearized DNA vector and improves the yield of the vector containing the appropriate insert.