Immunofluorescent Light Micrograph of mixed human- cancer cells in a culture: squamous carcinoma (at left), leukaemia (centre), & epithelial carcinoma (right). Cell nuclei stain blue. These cancers can be highly malignant, rapidly dividing growth forms. Both squamous (green) and epithelial (red) carcinoma occur on body surfaces: skin, or cells lining internal body organs. While leukaemia (orange) is a cancer of blood and blood-forming organs. Immunofluorescence is a staining technique which uses antibodies to attach fluorescent dyes to specific tissues and to molecules in the cell. Magnification: x400 at 35mm, x675 at 6x4.5cm size.