DNA migration. Fluorescence light micrograph showing DNA (Deoxyribonucleic Acid) migrating out from a cell nucleus. DNA has been made to glow yellow and the nucleus is seen as a yellow mass at upper centre. Fragments of DNA are seen around the cell as yellow-green granules. This fluorescence of DNA has been caused by a process known as in- situ hybridisation. Probes that stick to DNA molecules are added to a cell. The cell can then be treated with a chemical to make the probe fluoresce. In this way the location of DNA molecules within a normal cell can be assessed. Magnification: unknown.