The function of Atlantic salmon (Salmo salar L.) antibodies under extremes of pH and osmolarity

The ability of anti-MBP Atlantic salmon antibodies to bind to MBP was investigated using ELISA under a range of pHs (3–10) and osmolarities (100–1000mOsml−1) to determine the optimum binding conditions required for Atlantic salmon antibodies. The pH optimum was between pH7–8 with pH7·4 giving the highest level of antibody binding. However, the decrease in optical density was in excess of 60% at pHs 6·0 and 9·0 and in excess of 99% at pHs of 3·0 and 10·0. The optimum osmolarity required for antibody binding was in the range 100–400mOsml−1 with 330mOsml−1 giving the highest level of antibody binding. Above 400mOsml−1 there was a rapid decrease in antibody binding with the OD dropping by over 50% at all dilutions. This decrease was maintained at all osmolarities over 400mOsml−1