In cryobiology DMSO has been used as a cryoprotectant and is still an important constituent of cryoprotectant vitrification mixtures used to preserve organs, tissues, and cell suspensions. Without it, up to 90% of frozen cells will become inactive. It is particularly important in the freezing and long-term storage of embryonic stem cells and hematopoietic stem cells, which are often frozen in a mixture of 10% DMSO, a freezing medium, and 30% fetal bovine serum. In the cryogenic freezing of heteroploid cell lines (MDCK, VERO, etc.) a mixture of 10% DMSO with 90% EMEM (70% EMEM + 30% fetal bovine serum + antibiotic mixture) is used.||Synonyms:|Methyl Sulfoxide; Dimethylsulfoxide; DMSO||CAS No:|67-68-5||Molecular Formula:|C2H6SO||Molecular Weight:|78.13||Purity:|≥99%||Appearance:|Colorless, clear liquid at RT||Specific Gravity:|1.095-1.097||Boiling Point:|188-190°C||Congealing Temp:|18.3°C||Refractive Index:|1.4755-1.4775||pKa:|31.3||Water (KF):|≤0.1%||Titratable Acid:|≤5ml||Residue after Evaporation:|≤0.01%||Solubility:|Water (very soluble)||RNase:|None Detected ||DNase:|None Detected||Storage and Stability:|Store at RT. Stable for 12 months at RT after receipt.||Note:|DMSO will congeal easily and may remain a solid at cool temperatures. Warm slightly to return to liquid state.