Reference limits of bone and liver alkaline phosphatase isoenzymes in the serum of healthy subjects according to age and sex as determined by wheat germ lectin affinity electrophoresis.

Wheat germ lectin affinity electrophoresis was employed for quantitating the bone and liver isoenzymes of alkaline phosphatase (EC 3.1.3.1) in serum and for determining the reference limits of each isoenzyme activity in 488 healthy individuals. Bone phosphatase activity was detected even after bone growth, accounting for 60-70% of the total activity. An increase in bone phosphatase activity occurred in older females, but there was a decrease in older males. Liver phosphatase activity gradually increased with age in both sexes, males showing higher activity than females at all ages. Wheat germ lectin affinity electrophoresis of serum alkaline phosphatase is a simple and useful method for quantitating bone and liver alkaline phosphatase activities.