FLOW-CYTOMETRY AND RNA STUDIES

RNA was less studied by flow cytometry (FCM) in comparison to other ce llular components. Moreover, most of these studies were applied to the measurement of total RNA. Nevertheless, such a quantification, essent ially by the use of acridine orange, but also other dyes or dye combin ations, permitted the acquisition of important information about the g eneral metabolism, and the characterization of different tumoral cell types. More recently, FCM has been used to quantify specific mRNA, in two different approaches: the first one employes the sorting followed by RNA extraction and/or detection by specific radiolabeled probes; in the second approach, the use of fluorescence in situ hybridization (F ISH) on cells in suspension allowed the direct quantification of speci fic mRNA by FCM.