抗原抗体的反应有一定的量比关系,只有当二者的量处于一定比例时,才会出现可见的反应。如果抗体过量,就有可能不出现可见的凝集反应,这种免疫学现象被称为“前带现象”。在血型血清学检测中,直接抗人球蛋白试验(DAT)是判断红细胞是否被抗体致敏的重要实验,笔者最近在检测1份RhD阴性产妇的婴儿标本时发现过量的抗D致DAT检测为弱阳性的结果,出现了少见的所谓“前 The reaction of antigen-antibody has a certain amount of relationship, only when the amount of the two is in a certain proportion, the visible reaction occurs. If the antibody is in excess, it is possible that no visible agglutination will occur. This immunological phenomenon is called the ”prozone phenomenon.“ In blood group serological tests, the direct anti-human globulin test (DAT) is an important experiment to determine whether red blood cells are sensitized by antibodies. I recently detected an excess of anti-D-induced DAT in 1 sample of RhD-negative mothers Weak-positive results, the emergence of a rare so-called ”before