FIG. 2.

Performance of protein G-HRP against odontocete sera and calibration of positive and negative controls. (A) The performance of protein G-HRP in gELISA against sera from Brucella-infected bovine (Bos taurus) and dolphin (S. coeruleoalba) was tested using two buffer conditions: PBS-Tween (pH 7.7) and 0.1 M acetate buffer (pH 5). The standard error at all points was <5% of the values. (B) Serum samples from dolphins with high (+++), middle (++), low (+), and negative (−) optical density readings were selected as controls for iELISA and cELISA. All positive serum samples were agglutinated by RBT. The standard deviations were derived from eight independent assays in the course of 1 month of monitoring. The DB reaction is included as an in-set image indicating the intensity of the reactions. Values of the three positive and one negative serum samples did not significantly depart from the mean and maintained nonoverlapping limits of variation during 1 month of monitoring in the three ELISAs.