Enzyme immunometric assay for quantitative determination of anti-H.Pylori IgG in human serum or plasma
The genus Campylobacter comprises Gram negative bacteria 0.5~5um long and 0.2~0.5um in diameter. These bacteria have a typical curved, spiral single or multiple ‘’S‘’ shape. They are highly motile with a characteristic movement making them easy to identify in gresh preparations. Helicobacter Pylori (previously called Campylobacter pyloridis and successively Campylobacter pylori) was initially isolated by Warren and Marshall from biopsy samples taken from patients suffering from active chromic gastritis. Subsequently many other authors have confirmed the close association between this bacterium and gastroduodenal pathologies. In fact it is now clear that Helicobacter pylori is the principal etiologic agent in type B gastritis (chronic active antral gastritis) a pathology for which it appears to be the triggering and perhaps aggravating factor (debate continues on this point). Undoubtedly data are available which substantiate the predominant role of Helicobacter pylori in recurrent duodenal ulcer.
The DIAKEY Helicobacter Pylori IgG ELISA is enzyme immunoassay method (ELISA), where horseradish peroxidase is used as enzyme conjugate. During the first incubation, the sample anti-H.Pylori IgG antibodies binding with antigen, if any, are bound to the streptavidin coated wells. A wash cycle eliminates all unbound material, in the incubation that follows, a second antibody (anti-human IgG conjugated with horseradish peroxidase) will bind to the H.Pylori-antigen-antibody complex. After a further wash cycle a colorless Chromogen solution (Tetramethyl-benzidine, TMB) is added to the wells, where it yields a colored compound, by reacting with the peroxidase enzyme, Color development will be stopped by adding H2SO4. The color intensity, measured in a spectrophotometer at 450 and at 620nm, will thus be directly proportional to the anti-H.Pylori IgG antibody concentration in calibrators and samples.