Mixing two solvents is a common way to prompt folding
Conventional stop-flow mixers mixing times are limited by turbulence to ~ 1 ms
Turbulence is eliminated when dimensions are very small (laminar flow regime)
Observe folding at various times (positions) after mixing with UV fluorescence
Tryptophan is excited to a long-lived triplet state that is quenched upon contact with cysteine
The rates that are measured can determine the probability distribution of Trp-Cys distances and the intramolecular diffusion coefficient
