Our D-Amino Acid Assay Kits measures free D-Amino Acids (except for D-Glutamate and D-Aspartate) present in foods or biological samples in a 96-well microtiter plate format. D-amino acids are oxidatively deaminated by D-Amino Acid oxidase into the corresponding α-keto acid, ammonia, and hydrogen peroxide. The hydrogen peroxide is then detected with a highly specific colorimetric or fluorometric probe. Horseradish peroxidase catalyzes the reaction between the probe and hydrogen peroxide, which bind in a 1:1 ratio. D-amino acid levels in an unknown sample are calculated based on a known D-Alanine standard curve.