MICROEXTENSIONS ON CHANGS LIVER CELLS AS OBSERVED THROUGHOUT THEIR DIVISION CYCLE

Synchronized Chang's liver cells, harvested by trypsinization and inoculated onto glass coverslips, were observed after various intervals by placing the coverslips and cells in a scanning electron microscope. Interphase cells were seen to lie flat against the glass while cells preparing to divide retracted into a rounded-up configuration. Microextensions on cells in interphase were only a few microns long and extended from most of the cell surface. Longer microextensions extended from the base of cells rounded-up for division while those over the rest of the surface disappeared. It is suggested that some of the short microextensions of interphase cells attach to the glass and remain attached as the cell divides. These could serve to hold the cell in place during mitosis and to provide guidance for the daughter cells to spread over a previously prepared surface. © 1969.