Dimethyl Sulfoxide is ideal for use as a cryoprotectant. Also used in chemical reactions, in polymerase chain reactions (PCR) as a PCR cosolvent to help improve yields, especially in long PCR, and as a cryoprotectant vitrification agent for the preservation of cells, tissues and organs. DMSO is used in cell freezing media to protect cells from ice crystal-induced mechanical injury. It is used for frozen storage of primary, sub-cultured, and recombinant heteroploid and hybridoma cell lines, embryonic stem cells (ESC), and hematopoietic stem cells. DMSO is frequently used in the combinations with BSA or fetal bovine serum (FBS).