It is commonly measured clinically as a part of a diagnostic liver function test to determine liver health. Diagnostically, it is almost always measured in units/liter (U/L). In BioVision’s ALT Assay Kit, ALT catalyzes the transfer of an amino group from alanine to ⍺-ketoglutarate, the products of this reversible transamination reaction being pyruvate and glutamate. The pyruvate is detected in a reaction that concomitantly converts a nearly colorless probe to both color (λmax = 570 nm) and fluorescence (Ex/Em = 535/587 nm). The kit provides a rapid, simple, sensitive, and reliable test suitable for high throughput activity assay of ALT with a detection limit of 10 mU per well.