α-Ketoglutarate (α-KG) is a central metabolic intermediate, functioning both in the TCA cycle and as an amino-group acceptor in amino acid synthesis. Its concentration reflects cellular metabolic status, making its quantification vital for studies in energy metabolism, physiology, and disease biomarker development.

The α-Ketoglutarate Assay Kit provides a simple, sensitive, and robust method for quantifying α-ketoglutarate in serum, plasma, cells, and tissue lysates. In the assay, α-KG reacts with alanine via alanine aminotransferase (ALT) to generate pyruvate, which is oxidized by pyruvate oxidase (PO) to produce hydrogen peroxide (H₂O₂). In the presence of horseradish peroxidase, the generated H₂O₂ reacts with the Amplex Red probe to produce resorufin, a highly fluorescent red product. The fluorescence intensity or absorbance of resorufin is directly proportional to the α-KG concentration in the sample. 

Figure 1. Typical α-KG standard curve using colorimetric reading (left) and fluorometric reading (right).