[Attempts to purify strain K of the virus of classical swine plague]

In the treatment of spleens and lumph nodes of rabbits infected with strain K, with the use of freon 113 the virus was freed from proteins up to 92-96 per cent. The infective power of the purified virus proved equal to that of the initial non-purified virus proved equal to that of the initial non-purified virus, and this points to the full extraction of the virus itself. The antigenic properties of the purified virus were demonstrated through agar gel precipitation with normal and hyperimmune sera of pigs and rabbits and indirect immunofluorescence methods. This method of purification yields a virus that can be used in more precise immunologic studies as well as in the study of the morphology of the classic swine fever virus.