K-Gold® Substrate is a one-bottle stabilised chromogenic substrate for use with alkaline phosphatase (AP) based immunoassays that require sensitive detection of phosphatase enzymes. Neogen®’s ready-to-use K-Gold liquid formula does not require mixing of additional ingredients or stabilising agents, making it an ideal formula for AP kit manufacturers. K-Gold Substrate utilises the substrate p-nitrophenyl-phosphate (PNPP), which reacts with alkaline phosphatase (AP) to produce the chromophore p-nitrophenol. K-Gold substrate turns a deep yellow color in the presence of alkaline phosphatase (AP) labelled conjugate. Available Products K-Gold Substrate (PNPP) For research and manufacturing use only.