||Alanine aminotransferase (ALT), also called serum glutamate pyruvic transaminase (GPT), is a member of transferase family. It catalyzes the reversible transfer of an α-amino group between alanine and glutamate, and is an important enzyme in amino acid metabolism. ALT is found mainly in liver and small amount in heart, muscle, and kidneys. In healthy subjects, serum ALT levels are low. However, when cells are damaged, such as acute and chronic hepatitis, obstructive jaundice, carcinoma of liver, myocardial infarction, ALT may leak into the blood stream and the ALT levels are significantly elevated. Therefore, determination of serum ALT level has great clinical and diagnostic significance.