Figure 2. Western blot analysis of immunoglobulin (Ig) G and IgM against Tropheryma whipplei for children with gastroenteritis, Marseille, France. Total native antigens from T. whipplei were tested. A) Five patients without T. whipplei detected from stool samples but with positive Western blot serologic results. B) Eight patients infected with T. whipplei. MWM, molecular weight markers. Values on the right of each blot are in kilodaltons.