[A luminescent cytochemical method for the quantitative determination of activated phagocytes]

A method is suggested for scintillating activated neutrophils and monocytes by the intensity of their own fluorescence after incubation with nitroblue tetrazolium (NBT). Only NBT reducing, i.e. activated, phagocytes of the blood and purulent wounds fluorescence. Two types of fluorescence have been observed. Blue fluorescence, induced by UV irradiation, with a maximum within the range of 450-470 nm, is due to reduced pyridine nucleotides and is characteristic of dormant cells. Yellow-green fluorescence evoked by visible light, its maximum being observed at 535 nm, is induced by oxidized flavoproteins and is typical of the cells developing active metabolism. The ratio between cytofluorometrically measured fluorescence intensities of oxidized flavoproteins and reduced pyridine nucleotides is the energy indicator of phagocytosis activation.