The Amplite® Colorimetric Aspartate Aminotransferase Assay Kit is a sensitive, mix-and-read assay for measuring AST activity in biological samples. Aspartate aminotransferase (AST) is a key enzyme in amino acid metabolism and a widely used biomarker for liver and cardiac injury. Elevated AST levels in serum are commonly observed in conditions such as viral hepatitis, liver cirrhosis, myocardial infarction, and other forms of tissue damage. This assay employs a coupled enzyme reaction that produces a stable blue-colored product, with the signal measured at an absorbance ratio of A570 nm to A610 nm. The assay is capable of detecting as little as 2 mU/mL of AST activity in a 100 µL reaction volume. It is highly adaptable, with a straightforward protocol suitable for serum, plasma, and other biological fluids. The kit is ideal for clinical diagnostics, drug screening, and metabolic research applications.