Differential interference contrast (DIC) light micrograph of cells in the prometaphase stage of mitosis (nuclear division). The cell at left is in early prometaphase and the cell at right is in late prometaphase. Mitosis is the formation of two daughter nuclei from one parent nucleus. At prometaphase the chromatin has condensed but there is not yet complete attachment of the chromosomes to the spindle. During mitosis sister chromatids are separated to opposite ends of the cell. Two identical chromatids make up one chromosome, so each cell retains a copy of the parent cell's genetic information. Giemsa stain.