Fluorescence discrimination between diploid cells on their RNA content: a possible distinction between clonogenic and non-clonogenic cells.

Flow cytofluorimetric techniques, using acridine orange fluorescence to measure RNA and DNA simultaneously in EMT6 cells, have been employed to discriminate between three diploid DNA populations in vivo on the basis of their RNA content. Cells with the lowest RNA levels seem to be in the process of disintegration. Cells with the highest RNA levels correspond to those with the highest plating efficiency, and those with intermediate RNA levels are those with the lowest plating efficiency. In vitro studies have shown that log-phase cells have higher RNA levels than cells in the late plateau phase of growth.