This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables.
In most titrations, the amount of antibody is varied in the presence of a constant amount of antigen (Fig 2, top). The prozone is then the zone of antibody excess, resulting in an absence of antibody-antigen precipitation or agglutination. The postzone is the comparable zone of antigen excess.In some titrations, however (such as the slide latex agglutination test for cryptococcal antigen), antigen is varied in the presence of a constant amount of antibody (Fig 2, bottom). The zone of antibody excess then follows the zone of equivalence, while the zone of antigen excess precedes it. The terms prozone and postzone thus carry the reverse meanings.Perhaps more distinguishing terms are needed for this phenomenon.
Gordon MA. Postzone v Prozone-Reply. JAMA. 1982;248(6):646–647. doi:10.1001/jama.1982.03330060014013
Customize your JAMA Network experience by selecting one or more topics from the list below.