Antigenic analysis of coccidioidin and spherulin determined by two-dimensional immunoelectrophoresis

Immunological tests are valuable aids for diagnosis of mycotic infections and, in some cases, as objective guides for clinical management and prognosis. The usefulness of these procedures is limited to the extents that crude antigen preparations are employed, that these are difficult to standardize uniformly, and that they contain antigens common to several species of pathogenic fungi. Analysis by two-dimensional immunoelectrophoresis methods of the two crude preparations used for coccidioidomycosis demonstrated that coccidioidin contained at least 26 antigens, with 10 of these found also in spherulin. In addition, spherulin contained two antigens not demonstrated in coccidioidin. No single test detected all antigens present, and multiple procedures were required to display the complete array of antigens. A reference system was established for coccidioidin and precipitated immunoglobulins from a burro hyperimmunized with coccidioidin. Evaluation of the reference system demonstrated that it was highly reproducible with respect to the reagents used, to repeated tests by the same person, and to comparative tests by two individuals using the same reagents. Applications of this reference system for standardization of reagents, for detecting common antigens, for monitoring successive steps during fractionation of crude preparations, and for fingerprinting strains for ecological and epidemiological studies are presented.