Abstract: Insulin assays could be a valuable tool in assessing carbohydrate utilization in fish. Therefore, we conducted procedures to validate a non-radioisotopic Enzyme-Linked Immunosorbent Assay (ELISA) for detection of plasma insulin concentrations in Largemouth Bass (LMB), Micropterus salmoides. Wild caught LMB were subjected to oral glucose stimulation or fasted for 2 d. Farm-raised, pellet-trained bass were fed a commercial diet containing approximately 25% soluble carbohydrates. All three groups of fish were then bled and plasma was used for validation of the assay. A solid phase two-site enzyme immunoassay in which two monoclonal antibodies are bound to separate antigens on the insulin molecule was conducted using the Food and Drug Administrations Center for Veterinary Medicine validation of analytical procedures methodology. The results from this assay validation study indicate that an ELISA insulin kit could be used for experimental detection of blood plasma insulin concentrations in LMB. The linearity, precision and reproducibility of the data were acceptable. However, the accuracy is unproven as no "gold standard" for LMB insulin exists. This ELISA method would be most useful for the detection of insulin, general increases or decreases in insulin (insulin response) and general comparative trends in insulin concentration in LMB and possibly other fish.
D.T. Sink and R.T. Lochmann , 2006. An Enzyme-Linked Immunosorbent Assay for Sampling Blood Plasma Insulin Concentrations in Largemouth Bass, Micropterus salmoides. Journal of Animal and Veterinary Advances, 5: 1008-1013.