Thursday, October 2, 2008
2008 R&D 100 Winner
Fluorescence microscopy has already shown its great value in following the position of quantum dots, organic dyes, and fluorescent proteins. But revealing movements in three dimensions, with real-time observation, hadn’t surfaced until the recent development of the 3-D Tracking Microscope by researchers at Los Alamos National Laboratory, Los Alamos, N.M. This microscope builds on a laser-scanning confocal architecture, but differs in that optical fibers are used as spatial filters for four circular “pinholes”. Beam paths are directed through the fibers to independent single photon counting avalanche photodiodes. The two sets of fibers are positioned at 90° from each other and differ slightly in their distances to the tube lens, a distinction that allows positional sensitivity in the Z-plane. Whenever a fluorescent reporter under observation moves out of center, the microscope can estimate the direction, prompting the XYZ piezo positioning to re-center the reporter up to 1,000 times per second. The microscope can track protein-size particles (about 10 nm) at rates faster than many intracellular transport processes (down to nanoseconds).
Technology
Microscope
Developer
Los Alamos National Laboratory
