Placental alkaline phosphatase types and subtypes determined by agarose gel electrophoresis and separator isoelectric focusing.

Two techniques for phenotyping the human placental alkaline phosphatase system were developed: high-voltage agarose-gel electrophoresis and thin-layer separator isoelectric focusing on agarose. These methods enabled a more rapid and sensitive phenotyping of all common phenotypes than the traditionally employed starch-gel electrophoresis. An extended polymorphism of placental alkaline phosphatase was revealed by isoelectric focusing. The existence of two suballeles of Pl1 allele and two suballeles of Pl2 allele was postulated.