Dithiothreitol, as well called DTT or Cleland's reagent, quantitatively reduces disulfide groups (1) and is effective in sample buffers for reducing protein disulfide bonds prior to SDS gel electrophoresis (SDS-PAGE). The reducing thiol agent cleaves disulfide bonds between cysteine residues, thus totally unfolding proteins to allow a separation according to the molecular weight. It may also be used in lysis buffer in protein sample preparations. It is not only less pungent and less toxic than 2-mercaptoethanol, but as well a seven fold lower concentration of DTT (100 mM) than of 2-mercaptoethanol (5 % v/v, 700 mM) is needed. Oxidized form of DTT max. 0.5 %. Hygroscopic. Dithiothreitol, as well called DTT or Cleland's reagent, quantitatively reduces disulfide groups (1) and is effective in sample buffers for reducing protein disulfide bonds prior to SDS gel electrophoresis (SDS-PAGE). The reducing thiol agent cleaves disulfide bonds between cysteine residues, thus totally unfolding proteins to allow a separation according to the molecular weight. It may also be used in lysis buffer in protein sample preparations. It is not only less pungent and less toxic than 2-mercaptoethanol, but as well a seven fold lower concentration of DTT (100 mM) than of 2-mercaptoethanol (5 % v/v, 700 mM) is needed. Oxidized form of DTT max. 0.5 %. Hygroscopic.