TCEP is the next generation reducing agent. It is used as a hydrochloride salt (TCEP-HCl) with a molecular weight of 286.65 g/mol. It is soluble in water, odourless and non-toxic. It is used as a reducing agent to cleave disulphide bridges during protein chromatography and in SDS-polyacrylamide gel electrophoresis. TCEP is also used in the tissue homogenization process for RNA isolation. TCEP has the following benefits over DTT and 2-ME:
- More powerful reducing agent
- Irreversible reducing agent
- More hydrophilic
- More resistant to oxidation.
- It does not reduce metals used in IMAC
- It causes fewer ITC baseline artefacts
- TCEP is particularly useful when labeling cysteine residues with maleimides. TCEP can keep the cysteines from forming di-sulfide bonds and unlike dithiothreitol and β-mercaptoethanol, it will not react as readily and in certain conditions with the maleimide.