Stabilization of hog cholera virus by dimethyl sulfoxide.

The stability of hog cholera virus through five freeze-thaw cycles in the presence and absence of dimethyl sulfoxide was studied. In the absence of dimethyl sulfoxide the hog cholera virus titer was reduced 52% to 91% following successive freezing and thawing cycles. However, when dimethyl sulfoxide was added to the viral suspension the virus titer appeared to remain the same after the same number of freezing and thawing cycles.