Rapid Microfluidic Double-Jump Mixing Device for Single-Molecule Spectroscopy

We introduce a microfluidic double-jump
mixing device for investigating
rapid biomolecular kinetics with confocal single-molecule spectroscopy.
This device enables nonequilibrium dynamics to be probed, e.g., transiently
populated intermediates that are inaccessible with existing single-molecule
approaches. We demonstrate the potential and reliability of the method
on time scales from milliseconds to minutes by investigating the coupled
folding and binding reaction of two intrinsically disordered proteins
and the conformational changes occurring in a large cytolytic pore-forming
toxin.