Helicobacter pylori is an important etiologic cause of chronic infection
   of gastric mucus, chronic gastritis, peptic ulcers and gastric cancer in
   human. The aim of this study was to identify and characterize the dominant
   antigen of H.pylori, which is responsible for the humoral and cellular immune
   responses.

          Gastric biopsy of patients with gastric ulcers were sent to microbiology
   lab. First, samples were homogenized at sterile conditions, and then they
   were cultured in special medium and micro-aerophylic conditions.
   25 colonies of H.pylori were removed from culture medium and the whole-
   cell lysates were analyzed by sodium dodecyl sulfate-polyacrylamide gel
   electrophoresis. Immunoblots were performed using sera from H.pylori-
   infected persons . Specific H.pylori antibody responses in persons were
   analyzed by enzyme-linked immunosorbent assay.

          Two groups of bands appeared after staining of the SDS-PAGE with
   comassie blue. One group was within 55-97KD and the other were around
   20-24 KD. Western - blotting analysis detected a band around 55-97 KD,
   which is dominant antigen and responsible for immune response against
   H.pylori. Using ammonium sulfate as a precipitant for sera would have
   valuable effects in the westernblot results.

          As it is shown in the results , an antigen with MW=97 KD is immunodominant
   and stimulate patient’s immune system to produce antibody and can be
   candidate as a subunit vaccine in future.