Piran U, Riordan W J, Livshin L A
Ciba Corning Diagnostic Corp., Walpole, MA 02032, USA.
Clin Chem. 1995 Jul;41(7):986-90.
We developed a novel noncompetitive immunoassay format for monoepitopic analytes and describe here a model assay for triiodothyronine (T3), performed on Ciba Corning's ACS:180 analyzer. Acridinium ester (AE)-labeled bivalent anti-T3 was incubated with the sample, producing AE-anti-T3/T3 complexes and unreacted AE-anti-T3. Controlled-pore glass particles (CPG) with immobilized diiodothyronine (T2) were then added in excess, to bind AE-anti-T3 possessing two unoccupied binding sites but not AE-anti-T3 bound to one or two T3 molecules. Paramagnetic particles (PMP) with immobilized anti-AE were then added to the same cuvette to capture AE-anti-T3/T3 complexes; AE-anti-T3 bound to the surface of CPG, however, was not captured, because of steric hindrance. After the incubation, the PMP was magnetically separated to remove the liquid phase and the suspended CPG from the cuvette. The chemiluminescence associate with the PMP remaining in the cuvette was then measured. This noncompetitive T3 assay exhibited a 10-fold lower detection limit than the equivalent competitive T3 assay, i.e., 0.3 vs pg/test. Imprecision (CV) in the clinically significant range was 6% or less. The assay also displayed two- to sevenfold lower cross-reactivities and a wider dynamic range.
我们开发了一种用于单表位分析物的新型非竞争性免疫分析方法，并在此描述了一种在汽巴康宁公司的ACS:180分析仪上进行的三碘甲状腺原氨酸（T3）模型分析。将吖啶酯（AE）标记的二价抗T3与样品孵育，生成AE-抗T3/T3复合物和未反应的AE-抗T3。然后加入过量的固定有二碘甲状腺原氨酸（T2）的控孔玻璃颗粒（CPG），以结合具有两个未占据结合位点的AE-抗T3，但不结合与一个或两个T3分子结合的AE-抗T3。然后将固定有抗AE的顺磁性颗粒（PMP）加入同一比色皿中，以捕获AE-抗T3/T3复合物；然而，由于空间位阻，结合在CPG表面的AE-抗T3未被捕获。孵育后，通过磁力分离PMP，以从比色皿中除去液相和悬浮的CPG。然后测量比色皿中剩余的PMP相关的化学发光。这种非竞争性T3分析的检测限比等效的竞争性T3分析低10倍，即0.3对pg/测试。在临床显著范围内的不精密度（CV）为6%或更低。该分析还显示出交叉反应性低两到七倍，动态范围更宽。
