Colon cancer. Immunofluorescent light micrograph of human colon cancer cells. The nucleus of each cell is blue, surrounded by a fibrous mass of protein. Tubulin (green) is a protein used by cells during cell division, myosin (red) is muscle fibre. Mitotic cell division (at centre) is occurring. Blue condensed chromosomes are being split" apart by two tubulin spindles. Such irregular-shaped cells with large nuclei and cell divisions are characteristic of cancer cells. Colonic cancer is a common form of cancer. Immuno- fluorescence is a technique that uses antibodies to attach fluorescent dyes to specific parts of a cell. Magnification: x374 at 4.5x6cm size."