“…The fractions comprising each peak were pooled and tested for antibodies to typhoid 0, typhoid H, and paratyphoids A and B by standard agglutination procedures (10). Antibody activities associated with the first (pH 7.0, 0.01 M) and the last (pH 5.0, 0.3 M) chromatographic peaks were considered to contain 7S and 19S -y-globulins, respectively, on the basis of the behavior of these proteins on DEAE-cellulose (9,11,12). Although the first, or 7S, peak contains no 19S globulins, the last peak is contaminated by 7S protein, which could account for part of the antibody titers associated with this fraction.…”