techniques

Laboratory of Lisa Lapidus

Text Box: Requirements:
Long-lived Probe – Tryptophan triplet state
Efficient Quencher – Cysteine
Quenching on Contact – Electron Transfer

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

Microfabricated Mixer for observing folding dynamics as short as 10 ms

Scanning confocal microscopy image of tryptophan fluorescence after mixing

Scanning electron microscope image of mixing chip

Fluorescence Quenching by Potassium Iodide determines the mixing time (8 microseconds)