[Spectral characteristics of human white blood cells fluorochromed with acridine orange]

It has been shown that the ratio between the intensity of luminescence band in the red spectrum region (640 nm) and that in the green one (530 nm) of acridine orange fluorochromed cells fixed under certain conditions alpha=I640/I530 is a specific character. The latter can be used for automatic classification of bone marrow cells and perypheric blood and for diagnostics of some pathological states of the cell. It has been found that the type of the changes of the ratio of alpha=I640/I530 at photochemical bleaching of fluorochromed cells under irradiation (436 nm) depends on the level of cell differentiation. Completely differentiated mature cells are characterized by a simultaneous decrease of luminescence intensity, both in the red (640 nm) and green (530 nm) spectrum regions. In undifferentiated cells (especially at the blast stage) a decrease of luminescence intensity in the red region (640 nm) is accompanied by an increase of the luminescence intensity in the green region (530 nm) which may serve as an additional specific character. The descovere effect of photobleaching of undifferentiated cells is suggested to be due to the photodestruction of dimers of acridine orange bound with monohelical regions of DNA.