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

A 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, MrNV. 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.