Indirect-blocking ELISA for detecting antibodies against glycoprotein B (gB) of porcine cytomegalovirus (PCMV)

The major epitope region of the glycoprotein B (gB) gene of the porcine cytomegalovirus (PCMV), with a length of 270 bp, was cloned and expressed in Escherichia coli Rosetta (DE3). The major gB epitope was detected using an agar gel precipitation and Western blot analysis with the polyclonal antibodies specific for the major epitope. An indirect-blocking enzyme-linked immunosorbent assay (ELISA) was developed using the expressed major gB epitope as a coating antigen for the detection of PCMV antibodies. The results of the tests show that the indirect-blocking ELISA has 98% specificity and 97.8% sensitivity. No cross-reactions were observed between the major gB epitope and the antibodies against other virus, which indicates that the gB epitope is specific for PCMV antibodies. The indirect-blocking ELISA is a highly specific, sensitive method for detecting anti-PCMV gB antibodies.

► An indirect-blocking enzyme-linked immunosorbent assay (ELISA) was established by using the expressed major gB epitope as a coating antigen to detect the PCMV antibody-positive serum. ► The indirect-blocking ELISA is specific and sensitive. ► This is a practical ELISA method that can be used to develop a new PCMV antibody detection ELISA kit that should aid in the routine detection of PCMV.