Succinyl-CoA Synthetase (SCS, also called Succinyl-CoA ligase, Succinate Thiokinase) (EC 6.2.1.5) is a critical enzyme in the citric acid cycle and an important metabolic intermediate for porphyrin, heme and ketone body biosynthesis. It is located in the mitochondrial matrix and is a heterodimer composed of one α and one β subunit. In humans, Succinyl-CoA Synthetase deficiency causes the build-up of lactic acid leading to lactic acidosis, which can be fatal in infants. Measurement and analysis of SCS activity is useful for both mechanistic studies as well as for diagnostic purposes. In BioVision’s Succinyl-CoA Synthetase Activity Assay, SCS converts succinate into succinyl-CoA in the presence of ATP and CoA. Succinyl-CoA reacts with the Developer to form a colored product with strong absorbance at 450 nm. This assay kit is simple, sensitive, and high-throughput adaptable. It can detect less than 0.1 mU of Succinyl-CoA Synthetase activity in a variety of samples.