Two cell lines established from human stomach cancers were used in this experiment. After culture by the coverslip method, cells were fixed and coated with carbon and gold to be observed under the scanning electron microscope.
1. When the cells began to grow in a monolayer after the subculture, the boundaries between interphasic cells were indistinguishable. The nuclei in the interphasic cells were thinner than the surrounding cytoplasm and appeared concave. However, the nucleoli were prominent in the surrounding karyoplasm and appeared convex.
2. The cell which entered the mitotic stage rose spherically among the flat interphasic cells and stretched out many fine cytoplasmic processes (0.6μ thick) in all directions.
3. In the telophase, two daughter cells were connected with a bundle of many fine cytoplasmic processes.
4. In general, the mitotic cell surface was covered with a fine granular structure which was different in appearance from a microvilli-like structure. This structure is supposed to be due to the bubbling of mitotic cells observed by time lapse cinematography.