Abstract: A method of detecting cancer or precancerous conditions in a tissue or cell using fluorescence excitation spectroscopy. According to one embodiment of the method, a tissue is tested for cancer or a precancerous condition by exciting the tissue with substantially monochromatic light at 268 nm and then at 289 nm, with the resultant native fluorescence emitted from the tissue following each excitation being measured. A ratio of the fluorescence intensities, e.g., I.sub.289 /I.sub.268, is then calculated. If I.sub.289 /I.sub.268 is greater than 1.5, the tissue is cancerous or precancerous whereas if I.sub.289 /I.sub.268 is less than 1.5, the tissue is not cancerous or precancerous.

Abstract: A method and apparatus for examining a cell smear for the purpose of detecting the presence of cancerous and precancerous cells located therein. In a preferred embodiment, the method comprises illuminating at least a portion of the cell smear with light of a first wavelength, whereby native fluorescence is emitted therefrom. Next, the intensity of native fluorescence emitted from the illuminated area is measured at a second wavelength and at a third wavelength as a function of location within the illuminated area. The first, second and third wavelengths are chosen so that the ratio of fluorescence intensities at the second and third wavelengths is indicative of a carcinomatous condition. Next, the ratio of intensities measured at the second and third wavelengths is determined to obtain a value for each location within the illuminated area. Finally, a map is generated of all the cells present within the illuminated area using the calculated values.