β-Mercaptoethanol can act as an enzyme reactivator in systems necessitating reduction for activation, and has been commonly used to reduce disulfide bonds in order to separate protein subunits for use in electrophoresis.
M 1628 (OTTO) 2-Mercapto ethanol, for molecular biology, 99% Cas no 60-24-2 - used in some RNA isolation procedures to eliminate ribonuclease released during cell lysis. Numerous disulfide bonds make ribonucleases very stable enzymes, so 2-mercaptoethanol is used to reduce these disulfide bonds and irreversibly denature the proteins.