Sarcosine, a natural amino acid, plays important roles as intermediate in the metabolism of choline, methionine, glycine, glutathione, creatine, purine and serine, etc. Detection of sarcosine level has wide applications in research and development. Sarcosine Assay Kit provides an accurate, convenient measure of sarcosine in variety biological samples. In the assay, sarcosine is specifically oxidized to generate a product that converts a colorless probe to a product with intense red color (λmax = 570 nm) and which is also highly fluorescent (Ex/Em = 538/587 nm). Sarcosine is therefore easily detected by either colorimetric or fluorometric methods with detection range 1-10000 µM.