... simulta-neously observing single-molecule fluorescence changes and force-induced strand separations in dye-labeled double-stranded DNA duplexes.Prior attempts to marry optical trapping with single-moleculefluorescence ... and achieves spatially coincident opticaltrapping and single-molecule fluorescence, making this atrue combination of the two technologies.Results and discussionThe optical layout of our instrument ... variety of conditions and rates of loading (M.J.L., P.M.F., A.M. Engh, K.C.Neuman, and S.M.B., manuscript in preparation).ConclusionsWhen suitably combined, optical trapping and single-molecule...