2-DE gel obtained with T. gondii lysate antigen after silver nitrate staining. A. All proteins from T. gondii RH strain tachyzoites were separated by isoelectric focusing (pH 3–10), followed by SDS-PAGE electrophoresis on polyacrylamide gel (12% acrylamide), and then revealed by silver nitrate staining. B. Delineation of the IgM triplet zone between 75 and 100 kDa and numbering of all protein spots present. C. Close-up of the protein spots in the IgM triplet zone.