Caught Red-handed

http://www.economist.com/node/17843620

In order to diagnosize cancer at an earlier stage (benign tumors), a nice approach to 'track down' small tumors is highly sought after. This research group is able to make the tumors 'glow' with the help of a series of virus. The virus can infect the tumor cells and they also have the ability to cause the production of a fluorescent protein. When the virus replicates, more tumor cells will be infected. The result is that these tumor cells glows brighter and brighter, and they can thus be observed using a rather expensive camera (at this stage). While the normal biotechnology employs Green Fluorescent Protein (GFP), green light is not a good choice for the purpose because its frequency is too high for it to travel readily through human tissues. So red the fluorescent protein is chosen instead to carry out this mission (to rationalize, think about the relationship velocity of light = frequency x wavelength). This 'red shift' makes the strategy work - and the tumors are caught RED-handed.

Reference:

The Economist
Making cancer glow away
Jan 4th 2011