Alanine Transaminase Assay

Alanine Aminotransferase (ALT), also known as serum glutamic-pyruvic transaminase (SGPT), catalyzes the reversible transfer of an amino group from alanine to α-ketoglutarate. The products of this transamination reaction are pyruvate and glutamate. ALT is found primarily in liver and serum, but occurs in other tissues as well. Significantly elevated serum ALT levels often suggest the existence of medical problems, such as hepatocellular injury, hepatitis, diabetes, bile duct problem and myopathy. This colorimetric assay is based on a based on the oxidization of NADH to NAD in the presence of pyruvate and lactate dehydrogenase. The ALT activity is determined by assaying the rate of NADH oxidation, which is proportional to the reduction in absorbance at 340nm over time (ΔOD340nm/min).