Dimethyl sulphoxide protects cells against polypeptide toxins and poliovirus

The effect of dimethyl sulphoxide and other cryoprotective compounds on the sensitivity of cells to polypeptide toxins and to poliovirus was tested. In the presence of these compounds, which all affect membrane fluidity, the cells were protected against the toxic proteins and against poliovirus. The large protection obtained was not due to reduced binding and endocytosis of the toxins. Apparently, the cryoprotective compounds interfere with the entry of toxins and of the poliovirus genome across the cell membrane.