Detection of spring viraemia of carp virus (SVCV) with monoclonal antibodies

Monoclonal antibodies (MAbs) against spring viraemia of carp virus (SVCV), a severe disease in cyprinid fish, were prepared. Nine MAbs were characterised using Western blotting (WB) where all reacted with glycoprotein G, except for MAb 2E1, which showed no reactivity in WB. All nine MAbs showed specificity in an immunoperoxidase test. In ELISA assays, their titres ranged between 1:32 000 and 1:128 000. A panel of SVCV isolates from different European regions were set up and examined by sandwich ELISA assay using the MAbs at a concentration of 15 μg/ml. Only MAb 4C12/3C8 showed low sensitivity in most of the isolates at an absorbance of A450. Of the other MAbs, even the lowest absorbance value measured exceeded cut-off for evaluation of the whole reaction. No cross-reaction with the infectious haematopoietic necrosis virus (IHNV), viral haemorrhagic septicaemia virus (VHSV) or infectious pancreatic necrosis virus (IPNV) was demonstrated. 2E1 did not show cross-reactivity with PFRV classified in genogroup III–IV and reacted with a Czech SVCV isolate; its identity was confirmed by means of RT PCR assay. The others MAbs reacted positively with PFRV F4 reference strain, isolated from Esox lucius L. (genogroup III).