Osteosarcoma cells. Immunofluorescence light micrograph of human osteosarcoma cells stained to show cell proteins and organelles. The stains used here have highlighted the structural protein tubulin (green), the mitotic spindle-associated protein astrin, and wheat germ agglutinin (WGA, blue). Astrin ensures that the chromosomes are correctly aligned. In these non-mitotic cells, astrin is clustered in the nucleolus. WGA is associated with a sugar found in membranes and the nuclear envelope. Osteosarcoma is a type of bone cancer. Magnification: x1030 when printed at 10 centimetres wide.