Resolution of mitotic cells using laser scanning cytometry.
A microscope-based laser scanning cytometer (LSCM) has been developed that automatically measures multiple wavelength fluorescence and light scattering of cells on a microscope slide and generates lists of cytochemical and morphological features for each of thousands of cells in a typical sample. For a sample stained with a DNA stain, among the features generated are the value (DNA content), peak (chromatin condensation), and area (nuclear size), as well as the location of the cell on the slide. When combined with each other, these features give detailed resolution of the mammalian cell cycle, including the separation of mitotic from interphase cells. This is demonstrated under a variety of conditions, including cells that were fixed while in suspension and then adhered to a microscope slide, cytocentrifuge preparations, adherent cells fixed in situ on a microscope slide, on viable adherent cells, and on pathological tissue material. Galleries are shown of images of cells that were identified by the instrument as belonging to specific stages of the cell cycle, based on their biochemical staining, and were automatically relocated for viewing. The images are either epifluorescence images of the cells stained with the DNA fluorochrome or brightfield images of cells from slides that were restained with chromatic dyes.