Evaluation of monoclonal antibodies for generic detection of flaviviruses by ELISA

Three monoclonal antibodies (Mabs) specific for the envelope (E) protein of flaviviruses were evaluated for use in an antigen capture ELISA. Three combinations of Mabs and a combination of polyclonal antibodies (Pabs) were evaluated in antigen capture ELISAs for their ability to detect 18 flaviviruses. The Mab ELISAs detected 50% of flavivirus antigens with a sensitivity between 1 and 9 x 10(4) ng viral protein/ml, however, none of the ELISAs generic detection of flaviviruses, being unable to detect tick-borne flaviviruses and some mosquito-borne flaviviruses. The inability of the ELISAs to detect tick-borne flaviviruses is thought to be due to the conformation of surface epitopes, which the Mabs were unable to recognise. This war again observed using recombinant TEE virus prM/E protein as antigen in direct and antigen capture ELISAs. The Mabs reacted with the prM/E protein when it was denatured by binding directly onto the solid phase, but the antibodies were unable to detect the native protein in antigen capture ELISAs. The antigen capture ELISAs evaluated in this study were considered to be unsuitable for the generic detection of flaviviruses, but may provide a sensitive diagnostic assay for specific flavivirus infection.