A sandwich enzyme linked immunosorbent assay (S‐ELISA) for detection of MrNV in the giant freshwater prawn, Macrobrachium rosenbergii (de Man)

AbstractA sandwich enzyme‐linked immunosorbent assay (S‐ELISA) was developed to improve diagnosis of white tail disease of the giant freshwater prawn, Macrobrachium rosenbergii, caused by the nodavirus, Mr NV. Polyclonal antibodies were produced by immunization of Balb/C mice using a purified suspension of the virus and IgG anti‐MrNV were purified from ascitic fluid. A sandwich method was successfully developed, coating first with unlabelled antibody and detecting trapped antigens with a second biotinylated antibody. Reaction was demonstrated using an avidin–peroxidase conjugate. Tissue extracts from M. rosenbergii infected with MrNV or purified viral extracts (control) were successfully identified in an individual ELISA, thus confirming the validity of the method. This S‐ELISA should be the technique of choice for epidemiological studies of this disease and is a rapid and inexpensive assay with high specificity and sensitivity.