Abstract
The laser scanning cytometer (LSC) is a newly developed non-confocal laser scanning microscope with the advantages of a flow cytometer, an image analyzer, and a cytofluorometer. Using smears and imprints, we can quantitate the fluorescence intensity of cells quite rapidly, analyze the data, and observe cellular morphology as well.
Application of this technique to routine cytology offers many possibilities. It can enhance the objectivity of cytologic diagnosis. It opens up a new way of reevaluating the cyto-morphologic criteria for malignancy, and it permits the use of cytology to assess grades of malignancy, prognosis, chemotherapy sensitivitiy, and therapeutic efficacy.
Using standard procedures, nuclear DNA analysis on routine cytologic slides applying LSC was possible in 9 of 40 urine specimens; 13 of 20 specimens of body cavity fluids, bronchoalveolar lavage specimens, and washings of needles used for fine-needle aspiration cytology of the breast; and 3 of 20 archival Papanicolaou-stained slides. These results show that it is difficult to apply the LSC to cytology without future standardization of specimen preparation, methods of measuring smears and imprints with more or less degeneration, and means of analysis of complex DNA histograms. We demonstrated specimen preparation techniques specifically suited for use with the LSC. The techniques focus on cell isolation, preparation of smears with less cellular degeneration, and decoloration of Papanicolaou's stain prior to propidium iodide staining. Such techniques will ensure the reliability of the data obtained when the LSC is applied to cytology specimens.
