Mitosis. Fluorescence micrograph of two cells during metaphase of mitosis (nuclear division). During mitosis two daughter nuclei are formed from one parent nucleus. At metaphase, the chromosomes (blue) line up along the centre of the cell, and the spindles (green) grow from each pole to the chromosomes. Chromosomes are made up of two identical sister chromatids, which are separated into the two daughter nuclei, so that each daughter cell retains the parent cell's genetic information. Spindles are made of microtubules, which are part of the cell's cytoskeleton. Gamma tubulin, a protein found in spindle pole bodies, is red.