DL-Dithiothreitol

DTT is a reducing agent, which once oxidized forms a stable six-membered ring with an internal disulfide bond. It is an excellent reagent for maintaining SH groups in reduced state. DTT is used as a protecting agent that prevents oxidation of thiol groups, and used as a reducing agent for thiolated DNA. DTT is frequently used to reduce the disulfide bonds of proteins and, more generally, to prevent intramolecular and intermolecular disulfide bonds from forming between cysteine residues of proteins. DTT is often used along with sodium dodecylsulfate in SDS-PAGE to further denature proteins by reducing their disulfide bonds to allow for better separation of proteins during electrophoresis. DTT can also be used as an oxidizing agent. Its principal advantage is that effectively no mixed-disulfide species are populated, in contrast to other agents such as glutathione.