FIG. 1.

IgG binding to M. avium subsp. paratuberculosis antigens extracted with various organic solutions. Eight milligrams of M. avium subsp. paratuberculosis was suspended in 400 μl of each organic solution, agitated by vortex at room temperature for 2 min, and centrifuged, and 50-μl volumes of the supernatants were inoculated into each well of a 96-well microtiter plate. The supernatants were allowed to evaporate at room temperature overnight, after which the plate was used in an ELISA. After incubation of the wells with a buffer (open bars), NC serum (hatched bars), or PC serum (solid bars), IgG binding was detected by using biotin-labeled anti-bovine IgG antibody and HRP-labeled streptavidin. Abbreviations: MeOH, methanol; EtOH, ethanol; ProOH, isopropanol; ACN, acetonitrile; DCM, dichloromethane; CHCl₃, chloroform. Each hatched and solid bar represents the mean ± standard deviation (n = 3) of absorbance values at 415 nm. Each open bar represents the mean (n = 2) absorbance value at 415 nm. This experiment was repeated twice with similar results.