Annexin V-Flamma® 552 apoptosis detection kit, consisting of Flamma 552-conjugated annexin V, propidium iodide (PI) and the binding buffer, is a rapid and selective detection kit for labeling of externalized PS, an indicator of intermediate stages of apoptosis. Flamma® dyes display strong absorption, high fluorescence quantum yield and high photostability, and they maintain good fluorescence activity and stability after conjugation to biomolecules. The maxima of Ex/Em are at 550/565 nm. Annexin V-Flamma® 552 kit can be utilized in fluorescent imaging as well as for flow cytometry of apoptotic cells. This efficient apoptosis detection kit allows to accurately analyze mixed populations of apoptotic and normal cells.