Mechanics and Single-Molecule Interrogation of DNA Recombination: Supplemental Video 4
Abstract
A supplemental video from the 2016 review by Jason C. Bell and Stephen C. Kowalczykowski, "Mechanics and Single-Molecule Interrogation of DNA Recombination," from the Annual Review of Biochemistry.
Supplemental Video 4 Unwinding of a single molecule of λ DNA by RecQ, detected using fluorescent SSB and imaged using TIRF microscopy.
Initially, the dsDNA, tethered at each end to the surface of a flow cell, is fluorescent due to intercalation of the YO-PRO-1 dye molecules. As a solution containing 200 mM NaCl is introduced into the flow cell, the dye dissociates and fluorescence disappears. Subsequently, a solution containing 80 nM RecQ and SSBAF488 is introduced into the flow cell to initiate unwinding. The solution fills the channel 24 s into the video. The flow, when on, goes from left to right in the video. The elapsed time is indicated in hours:minutes:seconds and scale bar is 5 μm. Published with permission from Reference 73.