Billfishes

This study established a lateral flow competitive immunoassay with a colloidal gold-monoclonal antibody probe for the qualitative detection of sailfish serum albumin. The test involves mixing a tissue homogenate with a colloidal gold-monoclonal antibody suspension and applying the mixture to a strip of plastic-backed nitrocellulose membrane. The presence of albumin in a target sample competed with adsorbed antigen and prevented the appearance of a pink color on the nitrocellulose membrane. A non-target sample yielded a pink color when gold-labeled monoclonal antibodies bound to sailfish albumin previously absorbed to the nitrocellulose. Three gold particle sizes for antibody conjugation were evaluated and of these, 41 nm was optimal. The optimal pH for conjugation of anti-sailfish antibody to colloidal gold was 7.0. The assay requires only five minutes to perform and utilizes two solutions.

A monoclonal antibody (MAb) produced against sailfish (Istiophorus albicans) serum albumin (SFA)/(Rossi et al. 1992) was used in conjunction with rabbit polyclonal antibodies (PAbs) to formulate a sandwich-style enzyme immunoassay (sEIA). The sEIA specifically identifies sailfish tissues utilizing samples such as heart, kidney, white muscle, red muscle, and blood serum. The assay is sensitive to 20ng of SFA. Of the tissues tested, kidney yields the strongest signal. The entire assay is carried out in a 3cc syringe and, excluding sample preparation, can be executed in 30 minutes. No specialized equipment or training is required. MAbs were also produced against serum albumin purified from white marlin (Tetrapturus albidus) and Atlantic blue marlin (Makaira nigricans). These Mabs were examined for their utility in identification assays for these species.