FIG. 3.

Skin test protein cocktail dose titration. A skin test dose titration was determined for the protein cocktail comprised of ESAT-6, CFP-10, MPB70, and MPB83 in cattle that were naturally exposed to M. bovis (n = 19). The protein cocktail was administered at concentrations of 10, 5, and 1 μg for each antigen component. Protein cocktail and SICCT (PPD-B − PPD-A) responses measured at 72 h for each animal are represented by open circles, and the horizontal line provides the mean (±SEM), with results expressed as the difference in skin thicknesses (mm) between the pre- and post-skin test readings. The statistical difference between responses induced by the protein cocktails was determined by using ANOVA (*, P < 0.05; ***, P < 0.001).