The MaxDiscovery™ Alanine Transaminase (ALT) Enzymatic Assay Kit is a plate-based colorimetric enzymatic assay for the determination of the alanine transaminase enzyme in serum samples. Alanine transaminase (ALT) (also known as alanine aminotransferase or sGPT) is a metabolic enzyme expressed primarily in the liver. Damage to the liver causes the release of this enzyme into the blood. Elevation of ALT levels is an indication of liver damage and has been associated with liver injury. ALT levels are monitored routinely in patients with liver diseases. ALT is also a very useful tool for preclinical investigation of experimental drug formulations and ALT levels are commonly used to monitor and attenuate the hepatotoxic effects of experimental drugs in rodents.