ATP Assay Kit can be used to detect the level of ATP (adenosine 5'-triphosphate) in ordinary solutions, cells or tissues. ATP, as the most important energy molecule, plays an important role in various physiological and pathological processes of cells. Changes in ATP levels can affect cell function. Usually, cells undergoing apoptosis, necrosis, or in some toxic states will have decreased ATP levels, while high glucose stimulation can upregulate intracellular ATP levels for some cells. Usually, a decrease in ATP levels indicates impaired or decreased mitochondrial function, and the decrease in ATP levels during apoptosis usually occurs simultaneously with a decrease in mitochondrial membrane potential. Sample preparation is very simple. This kit provides ATP detection lysis buffer that can be used for cell and tissue lysis, and can be used for ATP detection after simple lysis. No need for cumbersome operations such as perchloric acid or trichloroacetic acid (TCA) extraction, or boiling after sample lysis. This kit is based on the fact that firefly luciferase (also known as luciferase) requires ATP to provide energy when catalyzing luciferin to produce fluorescence. When both firefly luciferase and luciferin are in excess, the production of fluorescence is directly proportional to the concentration of ATP within a certain concentration range, so the concentration of ATP in the solution can be detected with high sensitivity. This kit can detect ATP concentrations as low as 5nM when the sample volume is 100 μl. The concentration of ATP in conventional cell or tissue lysates is only 0.1-1μM, and the intracellular ATP level of some common cells is about 10nmol/mg protein. Moreover, the detection concentration range of this kit is very large, the detection upper limit can be as high as 10μM, and a good standard curve can be formed in the range of 10nM-10μM. Cell or tissue samples obtained by lysis with the ATP detection lysis buffer in this kit can not only be used for ATP detection, but also for protein concentration detection, SDS-PAGE or some conventional Western detection of easily soluble proteins.