Green Fluorescent Protein

The 2008 Nobel Prize in Chemistry was awarded to Osamu Shimomura, Martin Chalfie and Roger Tsien for their combined discovery and application of Green Fluorescent Protein (GFP).

GFP was isolated from a Pacific Northwest jellyfish by Shimomura, who noted its absorption of blue or UV light and resultant bright green fluorescence. It is now used widely in biochemistry and biology as a tag for proteins and as a marker for gene expression. In particular, the gene that encodes GFP can be spliced into the genome (of essentially any organism, from yeast to pigs or even bunnies...) in the vicinity of a gene that encodes a protein of interest. The expression of GFP is then linked to the expression of the protein under investigation. Whenever and wherever that protein is expressed is then easy to monitor because GFP is produced simultaneously!

(Image from Creative Commons)

You can probably imagine some of the other fascinating potential applications of GFP, ranging from tracking cancer metastasis and angiogensis in mice, to measuring calcium concentration in vivo.