von Lode Piia, Rainaho Jarmo, Pettersson Kim
Department of Biotechnology, University of Turku, Turku, Finland.
Clin Chem. 2004 Jun;50(6):1026-35. doi: 10.1373/clinchem.2004.031922. Epub 2004 Apr 8.
Human chorionic gonadotropin (hCG) is among the most common analytes available for point-of-care immunotesting, with most assays currently based on simple manual assay devices. However, as the importance of good analytical performance of rapid assays is increasingly emphasized, more sophisticated immunoassay techniques are needed to meet the future challenges of rapid yet quantitative POC testing.
We developed a simple, dry-reagent, all-in-one immunoassay for the quantitative measurement of hCG in whole blood, plasma, or serum. The noncompetitive assay equally measures intact, nicked, and hyperglycosylated hCG as well as nonnicked and nicked hCG beta-subunit with a rapid and simple procedure consisting of a 5-min, one-step incubation and, subsequent to washing, the measurement of time-resolved fluorescence directly from a wet well surface.
The assay had a detection limit (background + 3 SD) of 0.4 IU/L hCG. The within-run CV was <15% down to 2 IU/L, and the assay was linear to 6000 IU/L. The within- and between-run CVs in heparinized whole blood and plasma were </=10% throughout the measured range (4.0-4400 IU/L). The mean (95% confidence interval) difference between whole blood and plasma was -42 (-24 to -61)% without hematocrit correction and 6.5 (-14 to 27)% with hematocrit correction (n = 106). Regression analysis with the Diagnostic Products IMMULITE 2000 hCG method yielded the following: slope (SD), 1.02 (0.01); y-intercept (SD), -6 (10) IU/L; S(y|x) = 99 IU/L (n = 124; range, 1.6-4746 IU/L; r = 0.995).
Combined with the fully automated instrumentation, the 5-min, dry-reagent assay allows quantitative and reproducible determination of hCG in whole blood while sustaining the speed and simplicity of conventional rapid assays.
人绒毛膜促性腺激素（hCG）是即时检验免疫检测中最常见的分析物之一，目前大多数检测方法基于简单的手动检测设备。然而，随着快速检测良好分析性能的重要性日益受到强调，需要更复杂的免疫检测技术来应对快速且定量的即时检测未来的挑战。
我们开发了一种简单的干试剂一体化免疫检测方法，用于定量检测全血、血浆或血清中的hCG。该非竞争性检测方法能同等检测完整、切口和高糖基化的hCG以及未切口和切口的hCGβ亚基，其检测过程快速简单，包括5分钟的一步温育，洗涤后直接从湿孔表面测量时间分辨荧光。
该检测方法的检测限（背景+3SD）为0.4IU/L hCG。批内变异系数在低至2IU/L时<15%，检测线性范围达6000IU/L。在整个测量范围（4.0 - 4400IU/L）内，肝素化全血和血浆的批内和批间变异系数均≤10%。未进行红细胞压积校正时，全血和血浆之间的平均（95%置信区间）差异为 -42（-24至 -61）%，进行红细胞压积校正后为6.5（-14至27）%（n = 106）。与诊断产品公司的IMMULITE 2000 hCG方法进行回归分析得出以下结果：斜率（SD），1.02（0.01）；截距（SD），-6（10）IU/L；S(y|x)=99IU/L（n = 124；范围，1.6 - 4746IU/L；r = 0.995）。
结合全自动仪器，这种5分钟的干试剂检测方法能够在保持传统快速检测速度和简便性的同时，对全血中的hCG进行定量且可重复的测定。
