Dimethyl sulfoxide-13C2 (DMSO-13C2) is a labeled variant used as a polar aprotic solvent in organic synthesis, particularly in reactions involving nucleophilic substitution. It facilitates the penetration of active pharmaceutical ingredients through biological membranes, making it valuable in transdermal drug delivery systems. Employed in cryobiology as a cryoprotectant to preserve cells, tissues, and organs at low temperatures. Serves as a diagnostic aid in veterinary medicine for treating inflammatory conditions and certain toxicities. Due to its 99 atom % ¹³C isotopic labeling, it is especially utilized in analytical chemistry and biological research as a solvent for NMR spectroscopy, enabling precise tracking of molecular structure changes and carbon movements in chemical reactions. It also dissolves a wide range of compounds, including biomolecules like proteins and nucleic acids, aiding in the study of their structure and function in biological systems.