Infrared Proteins Give Deep View Inside Living Animals | Wired Science

Description

Infrared Proteins Give Deep View Inside Living Animals

A fluorescent protein found in an extremophile bacteria could give scientists an unprecedented view inside living animals.

The proteins, which glow with tissue-penetrating infrared light, could be used to tag cells in living animals, allowing researchers to watch real-time biological processes that have until now been hidden.

“Because their wavelengths penetrate tissue well, infrared-fluorescent proteins are suitable for whole-body imaging,” write University of California at San Diego biochemists Roger Tsien and Xiaokun Shu in a paper published Thursday in Science .

Tsien’s laboratory is best known for its work with green fluorescent protein , or GFP, which helped make it possible to observe cellular activity in detail as never before. GFP was originally discovered in jellyfish by Japanese biologist Osamo Shimomura and first used to illuminate cell activity by Columbia University neurobiologist Martin Chalfie. Tsien pioneered the next step in GFP’s refinement, engineering tens of thousands of markers that could be attached to any gene in the body.

Nearly every paper now written on gene or cell function involves GFP, either directly or by building on GFP-lit research. Its harnessing is considered one of the great advances of modern science, arguably on par with the development of the microscope — another tool that allowed researchers to investigate a previously invisible world. Tsien, Shimomura and Chalfie got the 2008 Nobel Prize in chemistry for their work.

But for all its acclaim, GFP has its limits. The wavelengths of light it emits and light used to observe this emission are quickly absorbed by cells, making it difficult to study living cells except in laboratory tissue cultures, microbes and extremely tiny animals. Those studies reveal little of what might be discovered by watching living tissues in complex organisms in real-time.

“The use of fluorescent proteins ...

Original URL

http://www.wired.com/wiredscience/2009/05/infraredcells/

http://www.wired.com/wiredscience/2009/05/infraredcells/