The use of chicken erythrocyte nuclei as a biological standard for flow microfluorometry.

Abstract

Tannenbaum, et al. advised the use of mithramycin-stained chick red blood cells (CRBC) as a biological standard for flow microfluorometry (FMF). The wavelength (488 nm) emitted by argon ion lasers in many commercial flow cytometers (e.g., Ortho Cytofluorograf) is too high to effectively excite mithramycin and precludes its use as a DNA specific fluorochrome in those machines. Another report by Cloch, et al. described the use of a fluorescent feulgen stain on CRBC which can be excited by 488 nm wavelengths; CRBC stained by this method show an anomalous DNA distribution due to the combined effects of cell refractility and cell orientation. To circumvent these problems of inappropriate laser wavelength and anomalous fluorescence, CRBC were stained with ethidium bromide (an analog of propidium iodide) in hypotonic citrate. Ethidium-bromide stained CRBC offer a useful alternative to mithramycin stained CRBC as a biological standard.