Immunoglobulin detection using three different conjugates and the mixture of Proteins A and G (PA + PG) by direct ELISA (A) and (B) frequency distribution of absorbance value in serum samples from four wild type rodents tested for anti-T. gondii antibodies by indirect ELISA. The dashed line is the calculated cut-off (Ab = 0.17). Normal distribution of negative sera was determined by Shapiro-Wilk (P = 0.421) and Jarque-Bera (P = 0.486) statistics. Arrows indicate positive samples as determined by their position to the right of the cut-off.