Figure. . . Two-dimensional (2-D) gel electrophoresis with silver stain results (on left) and Western blot results (on right) for 3 serum samples from patients who had visited Laos. The proteins were resolved by using 10% sodium dodecyl sulfate–polyacrylamide gel electrophoresis (Protean II xi chamber; Bio-Rad, Hercules, CA, USA). After migration, the gels were processed either by a silver-staining method compatible with mass spectrometry (4) or by transfer onto nitrocellulose membranes in a semidry blotting apparatus (Semi-Phor unit; Hoefer Scientific Instruments, San Francisco, CA, USA). The membranes were probed with horseradish peroxidase–conjugated goat anti-human secondary antibodies (Southern Biotech, Birmingham, AL, USA), and detection was achieved by enhanced chemiluminescence (ECL; GE Healthcare, Vélizy, France). APM, Acanthamoeba polyphaga mimivirus; ORF, open reading frame; A. castellani, Acanthamoeba castellani.