ADP Assay Kit (Colorimetric) is a quantitative colormetric determination of ADP at 450 nm.ADP is a product of ATP dephosphorylation and it can be rephosphorylated to ATP. Dephosphorylation and rephosphorylation occur via various phosphorylases and kinases. ADP is stored in platelets and can be released to interact with variety of purinergic receptors. ADP levels regulate several enzymes involved in intermediary metabolism. ADP conversion to ATP primarily occurs within the mitochondrion and chloroplast although several such processes occur in the cytoplasm. Conventionally, ADP levels are measured by luciferase/luciferin mediated assays after ADP is converted to ATP. However, the luciferase system is unstable and luminescence equipment is not generally available in most laboratories. ADP Assay Kit (Colorimetric) is suitable for measuring ADP levels in samples that contain reducing substances, which may interfere with oxidase-based assays. In this assay, ADP in the presence of ADP Enzyme Mix is converted to an intermediate, which reduces a colorless Probe to a colored product with strong absorbance at 450 nm. ADP Assay Kit is simple, fast and high-throughput ready. It can detect less than 20 µM of ADP in samples.