This is a method which quantifies the enzymatic activity of glutamic-pyruvate transaminase enzyme, commonly known as alanine transaminase or alanine aminotransferase (ALT), enzyme in a specified sample of blood plasma. ALT catalyzes the reversible transamination between alanine and 2-oxoglutarate to generate pyruvate and glutamate. Serum ALT level is used as an enzymatic marker for liver disease or damage.