What is Stopped Flow?
Absorbance, fluorescence, and circular dichroism are useful tools for monitoring kinetic changes of chemical and biological systems. However, changes often occur?on the millisecond scale, too fast for simple mixing. A stopped-flow accessory is used on the spectrophotometer to achieve fast mixing.Reagents are injected from two drive syringes through a mixer into the observation cell, where the changes in absorbance, fluorescence, or circular dichroism are recorded. Reactions ranging?from a few milliseconds to hundreds of seconds can be studied with the stopped-flow method.
Stopped Flow Applications
Typical research areas include reaction mechanisms, drug-binding processes, and determination of protein structure. Other applications include
- Ligand binding
- Coordination reactions
- Chemical reactions
- Electron transfer
- Fluorescence resonance energy transfer (FRET)
- Protein folding
- Enzyme reactions
- Protein-protein interactions
