Immunolocalization of CsMb in adult worm and metacercaria of C. sinensis . Rat anti-rCs Mb serum was used as the primary antibody and red fluorescent Cy3-labeled goat anti-rat IgG as the secondary antibody. Slides were observed under white light (panel A, C, E, G, and I) or under a fluorescence microscope (panel B, D, F, H, and J). No specific fluorescence was observed in panel B or H, which was probed with serum from rats immunized with PBS as a negative control. Intensive reddish-orange fluorescent signals were observed in the subtegumental and mesenchymal tissues of the adult worm (panel D and F; ×50) as well as the vitellarium of the metacercaria (panel J; ×200). Scattered fluorescent signals were detected in the tegument of the metacercaria. T, tegument. W, cyst wall.