Abstract: Outer membrane protein (OmpK) in Vibrio not only can stimulate humoral immunity and cellular immunity in the
body, but also can produce immune cross-reaction among strains of different serotypes. In this paper, cloning of sequences
and comparison with Genebank sequences were carried out to build Ompk phylogenetic trees of 20 Vibrio strains. A
prokaryotic expression system was used to express the OmpK of Vibrio parahaemolyticus B, and rabbit polyclonal antibody
was prepared after OmpK was purified and used to immunize rabbits. Antibody titer and specificity were detected by enzyme
linked immunosorbent assay (ELISA) and Western-blotting. Phylogenetic tree and gene sequence alignment results showed
that the Ompk gene was highly conservative in Vibrio and the similarity of nucleotide sequences was approximately 77%.
OmpK was successfully expressed in the prokaryotic expression system and rabbit polyclonal antibody was successfully
induced by immunization with the purified protein with a titer of 1:16 000 as detected by ELISA. Western-blotting results
confirmed that the antibody had good specificity. Vibrio Ompk gene sequence analysis and anti-Vibrio antibody preparation
will provide a theoretical basis for rapid and high-throughput detection of Vibrio in aquatic products..

Key words: Vibrio, Ompk, prokaryotic expression, purification, polyclonal antibody, immunological detection