Cytophotometric Data on Fluorochromed Cervical Cells<xref ref-type="fn" rid="FN1">2</xref>

Abstract

A simplified fluorophotometric device for measuring the light emission of the whole-cell area of single isolated cells is described. Ehrlich ascites carcinoma cells stained with the basic fluorochrome acridine orange were used for a model experiment. The sensitivity of the used photomultiplier 1P21 for the green-yellow emitted by the nuclear area was about 4 times greater than that for the metachromatic red of the cytoplasmic and nucleolar ribonucleic acid. Galvanometer readings over concentric cell areas of varying diameters showed that nuclear emission was mainly responsible for the total recorded fluorescence intensity. Photometric data obtained on single fluorochromed cervical cells gave mean emission values approximately 2 times higher for abnormal than for corresponding normal cells. Emission values of abnormal cells were distinctly above the level of a dividing line at 36.2 emission units and were well separated from normal cells. The differential staining of nucleus and cytoplasm by a basic fluorochrome with well-delineated nucleo-cytoplasmic boundaries is of advantage for detection of cellular atypia by visual observation. In addition, cytophotometric data can yield valuable evidence in closer identification and separation of degrees of cellular abnormalities, especially where cytologic classification and tissue findings are not conclusive.