Visualization of infectious pancreatic necrosis virus (IPNV) particles labeled with fluorescent probes

Increased sensitivity in antigen detection with fluorescent latex nanosphere-IgG antibody conjugates

IgG antibodies were conjugated to Kodak X-Sight nanospheres to develop fluorescent-labeled antibodies using two different synthetic routes: one involving the DTT reduction method, and the other involving Traut's Reagent modification method. These two methods result in different conjugation efficiencies and different performances in antigen detection. Western blotting shows that the nanosphere-IgG antibody conjugates synthesized using the DTT reduction method are more immunospecific than the conjugates synthesized using Traut's Reagent modification method. In addition, the conjugates synthesized using DTT reduction also show higher antigen detection sensitivity than other commercially available fluorescent-IgG antibody conjugates, including Alexa Fluor, Qdot, and CyDye conjugates.

The nucleoprotein and the viral RNA of infectious salmon anemia virus (ISAV) are localized in the nucleolus of infected cells

The infectious salmon anemia virus (ISAV), which belongs to the new genus Isavirus of the Orthomyxoviridae family, is an important pathogen of the salmon farming industry. Indirect immunofluorescence assays carried out with monoclonal antibodies specific for the nucleoprotein (NP) reveal differential staining of sub-cellular compartments in infected cells. Particularly interesting was the staining of the nucleolus, which showed co-localization with nucleolin in CHSE-214, EPC and SHK-1 cells infected with ISAV. These results were confirmed by co-immunoprecipitation studies showing an interaction between NP and nucleolin. In addition, in situ hybridization carried out with probes specific for each of the 8 RNA segments of ISAV showed that the genomic as well as the anti-genomic strands were also localized in the nucleolus. These results suggest a role of the nucleolus in the replication and/or in the packaging of the ISAV genome.