The sequence encoding 424 of 449 amino acids(aa)of CAV VP1(accounting for 95 per cent)were divided into two fragments,and were separately inserted into pGEX-5X-3 vector.They expressed in the form of GST fusion protein in E.coli. at high level,respectively.The anti-CAV polyclonal antibody was produced in mice immunized four times with the fusion protein,and its specificity was identified positive on CAV-infected MSB1 cells by indirect immunofluor...