Willey K P
J Immunol Methods. 1985 Nov 28;84(1-2):343-58. doi: 10.1016/0022-1759(85)90441-7.
Radioimmunoassays are usually developed empirically since there have been few established rules which cover general RIA behaviour. Evidence is presented which enables the delineation of 2 types of RIA with distinct group characteristics. (1) Simple RIA, conforming to the law of mass-action kinetics, is a result of univalent interaction. Examples of simple RIA include hapten assays and those using a monoclonal antibody (McAb). (2) Complex RIA occurs when antigen reacts multivalently with a polyclonal antiserum (PcAs). The formation of multicomponent complexes between a large molecular weight antigen and a PcAs is demonstrated using gel exclusion chromatography. These complexes are resistant to dissociation and are responsible for higher affinity, greater sensitivity and slower equilibration times compared to simple RIA. The assignment of an assay to either the simple or complex RIA group is dependent upon either the molecular size of the antigen or the use of a McAb. The consequent predictability of RIA behaviour enables a more rational approach to optimal assay design than current theory allows. It is advocated that the inability of a McAb to form multicomponent complexes is a major disincentive to their indiscriminate adoption in RIA.
放射免疫测定通常是凭经验开发的，因为几乎没有既定规则涵盖一般放射免疫测定行为。本文提供的证据能够区分出具有不同群体特征的两种放射免疫测定类型。（1）简单放射免疫测定符合质量作用动力学定律，是单价相互作用的结果。简单放射免疫测定的例子包括半抗原测定以及使用单克隆抗体（McAb）的测定。（2）当抗原与多克隆抗血清（PcAs）发生多价反应时，就会出现复杂放射免疫测定。使用凝胶排阻色谱法证明了大分子抗原与多克隆抗血清之间多组分复合物的形成。与简单放射免疫测定相比，这些复合物抗解离，具有更高的亲和力、更高的灵敏度和更长的平衡时间。将一种测定归为简单或复杂放射免疫测定组取决于抗原的分子大小或单克隆抗体的使用。放射免疫测定行为的这种可预测性使得在优化测定设计时能够采用比当前理论更合理的方法。有人主张，单克隆抗体无法形成多组分复合物是其在放射免疫测定中被不加区分采用的一个主要阻碍因素。
