Frengen J, Nustad K, Schmid R, Lindmo T
Department of Physics, University of Trondheim, Norway.
J Immunol Methods. 1995 Jan 13;178(1):131-40. doi: 10.1016/0022-1759(94)00251-q.
A new immunometric sequential binding assay has been developed in which the sample is first reacted with a solid phase binding partner in low concentration, and subsequently with a second binding partner at a higher concentration. The amounts of analyte bound to the two solid phase binding partners are separately measured, thus establishing a double standard curve. There is a shift between the two standard curves along the concentration axis. Thus an unambiguous determination of analyte concentration is obtained, even in the descending region of the curves where the 'hook' effect causes decreasing signal with increasing analyte concentration. A two-particle immunofluorometric assay for AFP based on this principle measured by flow cytometry, resulted in an assay with rapid binding (approximately 2 h), a detection limit of 0.1 kIU/l and a working range (0.3 to > 3 x 10(6) kIU/l) in excess of 7 log10 orders. Assay results compared well with those of an immunoradiometric assay.
已开发出一种新的免疫比浊顺序结合测定法，其中样品首先与低浓度的固相结合伴侣反应，随后与高浓度的第二种结合伴侣反应。分别测量与两种固相结合伴侣结合的分析物量，从而建立双标准曲线。两条标准曲线在浓度轴上存在偏移。因此，即使在曲线的下降区域，即“钩状”效应导致信号随分析物浓度增加而降低的区域，也能明确测定分析物浓度。基于此原理的甲胎蛋白双颗粒免疫荧光测定法通过流式细胞术进行测量，结果该测定法结合快速（约2小时），检测限为0.1 kIU/l，工作范围（0.3至> 3×10⁶ kIU/l）超过7个对数10级。测定结果与免疫放射测定法的结果比较良好。
