Direct assays of citrate synthase activity in cell lysates, tissues, and other biological samples. Linear detection range 0.50 to 120 U/L citrate synthase activity in 96-well plate assay. Simple and convenient. The procedure involves adding a single working reagent and reading the optical density at 5 min and 10 min at room temperature. High-throughput. Can be readily automated as a high-throughput 96-well plate assay for thousands of samples per day. Method: OD412nm; Samples: Cell lysates, tissues, and other; Procedures: 10 min