Double indirect-immunofluorescent labeling of cultured cells

Immunofluorescence is a powerful technique for identifying and localizing intra- and extra-cellular components both in histological sections and in cultured cells of plant or animal origin. Briefly, an antibody, raised against a specific component, is used as a label to map the distribution of the component in the specimen, and then visualized under the light microscope using a fluorescent dye (a "fluorochrome") such as rhodamine or fluorescein. These dyes are excited to fluoresce by microscope illumination of the appropriate wavelength. By using fluorochromes that differ both in the wavelength required for excitation and in the color of light emitted, several components can be mapped within the same specimen.