Alternating-laser excitation of single molecules.
Single-molecule fluorescence spectroscopy addresses biological mechanisms and enables ultrasensitive diagnostics. We describe a new family of single-molecule fluorescence methods that uses alternating-laser excitation (ALEX) of diffusing or immobilized biomolecules to study their structure, interactions, and dynamics. This is accomplished using ratios that report on the distance between and the stoichiometry of fluorophores attached to the molecules of interest. The principle of alternation is compatible with several time scales, allowing monitoring of fast dynamics or simultaneous monitoring of a large number of individual molecules.
Kapanidis
Achillefs N
AN
Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, USA. a.kapanidis@physics.ox.ac.uk
Laurence
Ted A
TA
Lee
Nam Ki
NK
Margeat
Emmanuel
E
Kong
Xiangxu
X
Weiss
Shimon
S
D004247:DNA / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D007834:Lasers; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014158:Transcription, Genetic
D004247:DNA