Chemical heterogeneity in cell death: combined synchrotron IR and fluorescence microscopy studies of single apoptotic and necrotic cells.

The combination of synchrotron IR microspectroscopy and fluorescence microscopy has led to the identification of specific IR signatures of apoptosis and necrosis at a single cell level. Apoptosis was induced by treatment of Fas+ tumor cell lines with anti-Fas monoclonal antibodies. Detection of the early and late stages of apoptosis was performed using conjugated annexin V-fluorescein isothiocyanate (AV-FITC) and propidium iodide.