Abstract
Serologic responses to the newly introduced rough Brucella abortus vaccine strain RB51 have been determined in a dot-blot format using γ-irradiated RB51 cells as the antigen. Because γ-irradiated cells are not easily prepared and the signal from cells was not always reliable, an alternative antigen was sought. Detergent extracts of B. abortus RB51 were prepared using zwittergent 3–14, Triton X-100, and sodium dodecyl sulfate (SDS) and examined in a dot-blot format. Zwittergent 3–14 extracts and γ-irradiated RB51 cells gave the same titers. Unlike γ-irradiated RB51 cells, zwittergent 3–14 extracts produced signals consistently, and the signals were easily interpreted. Triton X-100 extracts interfered with signal development, and SDS extracts resulted in a high background signal. Western blot analyses revealed several outer membrane proteins in the zwittergent 3–14 extract. The major antigens in the extract had apparent molecular weights of <20,000.