The brightly glowing green fluorescent protein, GFP, was first observed in the beautiful jellyfish, Aequorea aequorea in 1962. Since then, this protein has become one of the most important tools used in contemporary bioscience.

The chemical processes of cells are usually regulated by proteins. Tens of thousands of different proteins reside in a living organism, controling important chemical processes in munute detail.

By using DNA technology, researchers can now connect GFP to other important proteins. This glowing markerallos them to watch the movements, positions and interactions of the tagged proteins. For example, GFP can illuminate growing cancer tumors, show the development of Alzheimer's disease in the brain or the growth of pathogenic bacteria.

Thanks to GFP's green light scientists can now track a single protein under the microscope.