what is postzone phenomenon
Although the appropriate concept was probably communicated, the terminology used was not entirely correct.The prozone reaction refers to the absence of antibody-antigen precipitation in the presence of antibody excess. Since the authors refer to situations of antigen excess, the term prozone cannot correctly be used.Instead, absence of precipitation with excess antigen is described as the postzone phenomenon.This term should be applied to false-negative antigen test results in undiluted serum, which become positive on dilution. Furthermore, the point of maximum precipitation is named the zone of equivalence1 (Fig 1).lthough the appropriate concept was probably communicated, the terminology used was not entirely correct.The prozone reaction refers to the absence of antibody-antigen precipitation in the presence of antibody excess. Since the authors refer to situations of antigen excess, the term prozone cannot correctly be used.