Anticancer Inc. have developed a nude transgenic mouse, see pictures below.
Mouse under blue light (left) Same mouse under normal light (right)
When a blue light is shone on the mouse every cell (that contains actin) in its body will fluoresce green. Human cancers that express DsRed can be implanted into these mice. The cancers will give off red fluorescence. Now the cancer cells can easily be observed and monitored in live green mice. Allowing the researchers at Anticancer Inc. to observe metastasis (cancer cells moving around the body) and angiogenesis (blood vessels growing into the cancer and supplying oxygen and food).
Mouse blood vessels (green-GFP) in tumor (red-DsRed). Mouse with brain tumor expressing DsRed.