Oxalate (C2O4 2-), in the form of Oxalic acid is present in many foods and beverages (e.g. spinach, tea etc.). It accumulates in many plant tissues and play role in regulating pH, osmosis and calcium storage. In animals, oxalate is either absorbed from dietary intake or produced from glycolate metabolism in liver. Under normal conditions, the daily oxalate load can be excreted by kidney. However, hereditary defects can cause an increased level of oxalate, which leads to hyperoxaluria, and results in the formation of kidney stones.Therefore, measurement of oxalate level is useful for the prevention, diagnosis and monitoring of kidney stones. The Oxalate Assay Kit (Colorimetric) is an easy-to-use, sensitive and high throughput adaptable kit. In this assay, Oxalate reacts with Oxalate Converter and Oxalate Enzyme Mix to form an intermediate, which in turn reacts with a highly specific probe to generate color at 450 nm. The assay kit can detect Oxalate levels lower than 20 μM.