Western blot. In the first step, (1) a polyacrylamide gel electrophoresis is performed to separate ...

Western blot. In the first step, (1) a polyacrylamide gel electrophoresis is performed to separate the proteins of the virus or other pathogen. Next, (2) the separated proteins are transferred to nitrocellulose. The nonspecific binding sites of the nitrocellulose paper are blocked. (3) The paper is cut into strips, each strip is used to diagnose 1 patient. The steps (3–5) are to perform an indirect EIA. The patient sera containing the primary antibody to the viral proteins is added (3). After washing, (4) a secondary labeled antibody is added and after washing, (5) the substrate is added.