Native Human alkaline phosphatase is a liquid preparation of purified alkaline phosphatase derived from human placenta. Alkaline phosphatases are ubiquitous enzymes, occuring an species from bacteria to higher vertebrates, including man. They catalyse the hydrolysis of phosphate monoesters at basic pH values. In man there are four forms of alkaline phosphatase depending on tissue expression patterns. The four types are 'intestinal ALP', 'Placental ALP', 'germ cell ALP' and 'tissue non-specific ALP', also known as liver/ bone/ kidney ALP.