Department of Biotechnology, University of Turku, Turku, Finland.
Clin Chim Acta. 2012 Dec 24;414:70-5. doi: 10.1016/j.cca.2012.08.027. Epub 2012 Sep 4.
Cardiac troponins are the preferred and recommended biomarkers of myocardial infarction. Unfortunately, most of the current commercial assays do not meet the guideline recommendations for sensitivity and low-end precision. Therefore, improvements in their analytical performance are still needed.
Cardiac troponin I (cTnI) immunoassay was developed. The assay utilized a monoclonal antibody and a F(ab')(2) antibody fragment immobilized onto the microtiter wells for capturing, and a monoclonal antibody covalently conjugated to fluorescent europium(III)-chelate-dyed nanoparticles for detecting. Following a 15-min incubation of the sample and nanoparticle-bioconjugates in the capture wells, cTnI was quantified directly from the washed well surface by time-resolved fluorometry.
The limits of detection and quantification were 0.0020 μg/l and 0.012 μg/l, respectively. The response was linear in the measured range of 0.003-9.6 μg/l. The within-run imprecisions were 9.8, 5.1, 7.7 and 5.4%, and the total imprecisions were 13.1, 10.4, 9.0 and 8.7% at cTnI levels of 0.007, 0.051, 0.52 and 2.62 μg/l, respectively. Plasma recoveries of added cTnI were 72-119%. Regression analysis with Innotrac Aio! 2nd generation cTnI assay yielded a slope (95% confidence intervals) of 1.197 (1.141 to 1.253) and y-intercept of 0.216 (-0.128 to 0.561)μg/l (S(yx) = 2.176 μg/l, n = 212, r = 0.945).
The developed immunoassay based on europium(III)-chelate-dyed nanoparticle label allows rapid and sensitive measurement of cTnI.
肌钙蛋白是心肌梗死的首选和推荐生物标志物。不幸的是，目前大多数商业检测方法在灵敏度和低端精度方面都不符合指南建议。因此，仍需要改进其分析性能。
开发了心肌肌钙蛋白 I(cTnI)免疫测定法。该测定法使用单克隆抗体和固定在微孔板上的 F(ab')(2)抗体片段用于捕获，以及与荧光铕(III)-螯合染料纳米颗粒共价结合的单克隆抗体用于检测。在样品和纳米颗粒-生物缀合物在捕获孔中孵育 15 分钟后，通过时间分辨荧光法直接从清洗后的孔表面定量 cTnI。
检测限和定量限分别为 0.0020μg/l 和 0.012μg/l。在 0.003-9.6μg/l 的测量范围内，响应呈线性。批内精密度分别为 9.8%、5.1%、7.7%和 5.4%，cTnI 水平为 0.007μg/l、0.051μg/l、0.52μg/l 和 2.62μg/l 时总精密度分别为 13.1%、10.4%、9.0%和 8.7%。添加 cTnI 的血浆回收率为 72-119%。与 Innotrac Aio!2 代 cTnI 测定法的回归分析得出斜率（95%置信区间）为 1.197（1.141 至 1.253）和 y 截距为 0.216（-0.128 至 0.561）μg/l（S(yx) = 2.176μg/l，n = 212，r = 0.945）。
基于铕(III)-螯合染料纳米颗粒标记的开发免疫测定法允许快速和敏感地测量 cTnI。
