Abstract: A pair of primers was designed based on the genome sequence of hemorrhagic enteritis virus VAS strain, the complete gene of penton with a size of 1347 bp was amplified by PCR, and then cloned into plasmid expression vector pET-32a (+), the obtained positive clone was named pET-32a-penton. The pET-32a-penton was transformed into E.coli BL21, after inducing expression and purification of the protein in gel slices, about 70 ku recombinant fusion protein was obtained and used to immunize New Zealand White rabbits to prepare uni-factor serum against penton protein. Indirect ELISA was used to detect the antibody titer. The results showed that the antisera titer was greater than 1:40000. The method to get the efficient uni-factor serum was simple and low-cost, which laid a foudation for detection of group Ⅱ avian adenovirus.

Key words: group Ⅱ avian adenovirus; penton protein; uni-factor serum