Used as a labeling reagent in mass spectrometry for the identification and quantification of proteins and peptides. It is particularly valuable in proteomics research, where it helps in studying protein interactions, modifications, and functions. The deuterium labeling allows for precise tracking and differentiation of molecules in complex biological samples. Additionally, it serves as a methylating agent in organic synthesis, introducing methyl groups into target molecules to modify their chemical properties or to create deuterated analogs for research purposes. Its application extends to the development of pharmaceuticals, where it aids in the synthesis of deuterated drug compounds, enhancing their metabolic stability and efficacy.