CP204L and E183L genes which encode major antigenic proteins p32 and p54, respectively, of the African swine fever (ASF) virus were amplified by PCR and expressed in recombinant baculovirus. Each recombinant protein was recognized as a single band in baculovirus infected insect (SF21) cells by SDS-PAGE. Both proteins, p32 and p54, were detected in SF21 cells and only p32 was secreted into the extracellular medium. These two recombinant proteins were used in Western blot analysis for ASF antibody detection in sera from experimentally infected pigs and field sera collected at ASF World Reference Laboratory (Centro de Investigacion en Sanidad Animal) in Spain. Specific reactions were observed between these recombinant proteins and the test sera, indicating that p32 and p54 are useful as diagnostic reagents for serological tests. Protein p54 showed better reactivity than p32 in antibody detection, especially in the early stage of infection. However, in order to diagnose ASF accurately, both proteins should be used in Western blot analysis. ELISA using recombinant proteins is under development. (Lab. of Diagnosis, Department of Exotic Disease TEL +81-42-321-1441)
