Analyzing single protein molecules using optical methods.

Studies on single protein molecules have advanced from mere proofs of principle to insightful investigations of otherwise inaccessible biological phenomena. Recent studies predict a tremendous number of possible future applications. The long-term vision of biologists to watch single molecular processes in real time by peering into a cell with three-dimensional resolution might finally be realized. Another fascinating perspective is the identification and selection of single favorable variants from complex libraries of diverse biomolecules.