Abstract: The invention describes a new process for the production of anti-viral diagnostics, as well as an example of one antibody useful in detecting a wide variety of pathogenically important alphaviruses. The process includes, but is not limited to, the isolation of monoclonal antibodies directed against internal viral components. Such antibodies may be generated by conventional immunization in vivo or in vitro using subviral particles or synthetic peptides corresponding to specific viral proteins. Alternatively, synthetic peptides derived from the cytoplasmic domains of envelope proteins may be used to elicit monoclonal idiotypic and anti-idiotypic antibodies following immunization in vitro and/or in vivo.The anti-alphavirus antibody included in the invention is an example of the type of reagent produced. It was produced as an anti-idiotype against monoclonal antibodies to a synthetic peptide derived from Semliki Forest virus.