Storage and application of DTT

DTT (dithiothreitol) is a commonly used reducing reagent in the laboratory and is often used for protein preservation and reduction of protein disulfide bonds. DTT is characterized by its high susceptibility to oxidation and poor stability. Generally, DTT can be stored in -20°C for up to several years. DTT is a very strong reducing agent whose reductibility is largely due to the conformational stability of its oxidized six-membered ring (containing disulfide bonds). Its redox potential is -0.33V at pH 7.

The storage of DTT

DTT is a commonly used reducing agent, which has anti-oxidation effect and is imported and packaged. DTT has a similar effect compared to mercaptoethanol, but the pungent odor of DTT is much smaller and the toxicity is much lower than that of mercaptoethanol. Moreover, when DTT is 7 times lower than the concentration of mercaptoethanol, the effects are similar. But the price of DTT is slightly higher. General storage conditions for DTT powder: stored at -20°C. The 1M DTT solution can be stored at -20°C for more than 2 years.

DTT is less stable due to its ease of oxidation by air; however, cryopreservation or treatment in an inert gas can extend its useful life. Due to the low nucleophilicity of protonated sulfur, the effective reduction of DTT decreases with decreasing pH; Tris(2-carboxyethyl)phosphine HCl (TCEP hydrochloride) can be used as a low pH condition. A substitute for DTT, and it is more stable than DTT.

The application of DTT

One of the uses of DTT is as a reducing agent and deprotecting agent for thiolated DNA. The thiolated DNA terminal sulfur atom tends to form a dimer in solution, especially in the presence of oxygen. This dimerization greatly reduces the efficiency of some coupling reaction experiments (such as the immobilization of DNA in biosensors); while adding DTT to the DNA solution and removing it after a period of reaction, the dimerization of DNA can be reduced.

DTT is also often used for the reduction of disulfide bonds in proteins and can be used to prevent intramolecular or intermolecular disulfide bonds of proteins formed between cysteines in proteins. However, DTT often cannot reduce the disulfide bonds embedded in the protein structure (solvent unreachable). The reduction of such disulfide bonds often requires denaturation of the protein (heating at high temperature or adding a denaturing agent such as 6M guanidine hydrochloride, 8M urea or 1% SDS). On the contrary, according to the difference in the rate of reduction of disulfide bonds in the presence of DTT, the degree of embedding can be judged.

Related links: DTT

Edited by Suzhou Yacoo Science Co., Ltd.