Sablefish (Anoplopoma fimbria) are an emerging aquaculture species native to the northern Pacific Ocean along the coasts of North America, Russia, and Japan. Recent investment in culture techniques has optimized and reduced the costs of juvenile production, however further investigation of sablefish is required to understand and manage diseases associated with their production.
This work produced a monoclonal antibody (mAb), designated UI-25A, against the heavy chain of sablefish IgM and subsequently developed an ELISA to measure circulating antibodies within sablefish plasma. Plasma collected from adult sablefish was donated by Memorial University, and IgM was isolated using a mannan binding protein column (Thermo Fisher Scientific) . Purity of IgM was confirmed via SDS-PAGE before it was used to immunize BALB/c mice . Once specific antibodies to sablefish IgM were detected , spleen cells from mice were harvested and fused to mouse myeloma cell line X63 AG8.653. This resulted in 32 unique hybridoma colonies producing antibodies specific to sablefish IgM. Of these candidates, 4 were chosen for further testing (1, 9, 25, 30) and were confirmed to bind to the heavy chain portion of sablefish IgM (Figure 1).
An ELISA was developed using UI-25A to detect anti- Aeromonas salmonicida antibodies within sablefish plasma. This tool successfully detected high antibody levels in vaccinated fish and low signals in unvaccinated fish. The UI-25A mAb has potential to aid in the development of sablefish vaccines as well as further research into mechanisms of their immunity during pathogen infection.