Prostate cancer cell spheroid, LM

Confocal micrograph of a 3-dimensional reconstruction of a hollow multi-cellular prostate tumour spheroid (cluster of cells). Cell nuclei have been stained with the fluorescent dye propidium iodide and are visible in blue. The spheroid is a 3D system used to test the therapeutic activity of anti-cancer drugs and can reduce the need for research on animals. Diameter of the spheroid is approximately 250 micrometres.