Prevention of Freezing Damage to Living Cells by Dimethyl Sulphoxide

Abstract

Polge, Smith and Parkes¹ first reported the protective action of glycerol against the adverse effects on spermatozoa of freezing and thawing. Lovelock² found that the protective action of glycerol was shared with a number of other neutral solutes of low molecular weight, including methanol, acetamide and glyceryl monoacetate. Using the extent of hæmolysis of red blood-cells as a measure of damage by freezing, it was concluded that the principal protective action of the neutral solutes was a simple consequence of their ability to prevent the excessive concentration of electrolytes and other substances that otherwise occurs on freezing. The protective property is limited to substances that are in themselves not toxic, have a low molecular weight, a high solubility in aqueous electrolyte solutions and an ability to permeate living cells. The number of solutes capable of fulfilling these conditions is small, and so far glycerol most closely approaches the ideal protective agent. Some cells, however, are impermeable to glycerol, for example, bovine red blood cells, and with these glycerol is of little use in their preservation by cold storage. An alternative solute with a greater permeability to living cells is dimethyl sulphoxide. This communication reports the protective action of dimethyl sulphoxide against freezing damage to human and bovine red blood cells and to bull spermatozoa.