The relevance of flow cytometry for biochemical analysis

Flow cytometry (FCM) allows the simultaneous measurement of multiple fluore scences and light scatter induced by illumination of single cells or micros copic particles in suspension, as they flow rapidly through a sensing area. In some systems, individual cells or particles may be sorted according to the properties exhibited. By using appropriate fluorescent markers, FCM is unique in that multiple structural and functional parameters can be quantif ied simultaneously on a single-particle basis, whereas up to thousands of b iological particles per second may be examined. FCM is increasingly used fo r basic, clinical, biotechnological, and environmental studies of biochemic al relevance. In this critical review, we summarize the main advantages and limitations of FCM for biochemical studies and discuss briefly the most re levant parameters and analytical strategies. Graphical examples of the biol ogical information provided by multiparametric FCM are presented. Also, thi s review contains specific sections on flow cytoenzymology, FCM analysis of isolated subcellular organelles, and cell-free FCM.