International standard for anti-canine-distemper serum.

The Central Veterinary Laboratory, Weybridge, England, was requested by the WHO Expert Committee on Biological Standardization to obtain suitable material for an international standard for anti-canine-distemper serum and to arrange a collaborative assay. Seven laboratories in 6 countries assayed a batch of anti-canine-distemper serum against 3 test preparations. On the basis of the results obtained, the material has been established as the International Standard for Anti-Canine-Distemper Serum and the International Unit of Anti-Canine-Distemper Serum has been defined as the activity contained in 0.0897 mg of the International Standard.