Avian reovirus (ARV) structural protein, sigmaC, the prime candidate for vaccine against ARV, was expressed using a baculovirus/insect cell system. The expressed protein remained intracellular and reached 96 mug/10(6) cells. Total product yield from a 200 ml suspension culture was 19 mg. When the protein was fused with a histidine tag and an enterokinase (EK) cleavage site, purification of 94% was achieved in a single step. The histidine tag was removed by EK.