Lanthanide polymer-labelled antibodies were investigated to improve the analytical figures of merit of homogeneous immunoassays with inductively coupled plasma mass spectrometry (ICP-MS) detection for multiplexed biomarker analysis in human serum samples. Specific monoclonal antibodies against four cancer biomarkers (CEA, sErbB2, CA 15.3 and CA 125) were labelled with different polymer-based lanthanide group to increase the number of metal labels per binding site. After the immunoreaction of the biomarkers with the specific antibodies, antigen-antibody complexes were separated by size-exclusion chromatography followed by ICP-MS detection. The polymer label could be loaded with 30-times more atoms of the lanthanide that the lanthanide-DOTA complex traditionally used for this purpose elsewhere [1] which resulted in a 10-fold improvement in both sensitivity and detection limits. Analytical figures of merit obtained with the lanthanide polymer labelling strategy make the detection of the biomarkers feasible below the threshold reference values used in clinical analysis. This labelling method was successfully validated by analyzing a control human serum spiked with the four biomarkers at three different concentration levels. For all the biomarkers studied, the recovery values ranged from 95% to 110% whereas inter-assay and intra-assay precision were lower than 8%. Results obtained with this approach were equivalent to those obtained by heterogenous-based immunoassays based on the detection by electro-chemiluminescence or ELISA. However, the method developed offers better analytical figures of merit using a smaller amount of sample.

中文翻译：

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用于通过尺寸排阻色谱-电感耦合等离子体质谱法多重测定人血清样品中生物标志物的镧系元素聚合物标记

研究了镧系元素聚合物标记的抗体，以提高均相免疫测定的分析品质因数，采用电感耦合等离子体质谱 (ICP-MS) 检测对人血清样品中的多重生物标志物进行分析。针对四种癌症生物标志物（CEA、sErbB2、CA 15.3 和 CA 125）的特异性单克隆抗体用不同的基于聚合物的镧系元素进行标记，以增加每个结合位点的金属标记数量。在生物标志物与特异性抗体发生免疫反应后，通过尺寸排阻色谱分离抗原-抗体复合物，然后进行 ICP-MS 检测。与其他地方 [1] 传统上用于此目的的镧系元素-DOTA 复合物相比，聚合物标签可以装载 30 倍多的镧系元素原子，从而使灵敏度和检测限提高 10 倍。使用镧系元素聚合物标记策略获得的分析品质因数使生物标志物的检测在临床分析中使用的阈值参考值以下变得可行。通过分析掺有三种不同浓度水平的四种生物标志物的对照人血清，成功验证了这种标记方法。对于所有研究的生物标志物，回收率值范围为 95% 到 110%，而批间和批内精密度低于 8%。用这种方法获得的结果与基于电化学发光或 ELISA 检测的基于异质性的免疫测定法获得的结果相同。然而，所开发的方法使用更少量的样品提供了更好的分析品质因数。