Spectroscopic Study of Human Leukocytes

FTIR and auto-fluorescence techniques, based on the monitoring of endogenous molecules, are able to discriminate between normal and leukemic white blood cells. MIR spectra were measured at 4 cm(-1) resolution on 6 batches of normal lymphocytes and leukemic Daudi cells, centrifuged and dried on a BaF2 window. The finger-print region (800-1800 cm(-1)) of each spectrum was selected, detrended by subtraction of a straight tangent base line and normalized at the same area. Significant differences were found in the relative absorbance distribution within the range analyzed between normal and malignant cells. Epifluorescence microscopy techniques were employed on living leukocytes and Daudi cells. Fluorescence was detected by a digital CCD camera. Spectra were measured by an optical multichannel analyzer coupled to the microscope. Fluorescence was located at cytoplasmic-level, thus probably related to the metabolic processes of the cells. Photophysical properties appear different among the normal leukocyte populations and between normal and leukemic cells as far as spatial distribution and light spectrum and intensity is concerned.