Department of Analytical Chemistry, Nutrition and Food Sciences, University of Alicante, PO Box 99, 03080 Alicante, Spain.
CNRS/UPPA, Institute of Analytical and Physical Chemistry for the Environment and Materials, IPREM - UMR 5254, Hélioparc, 2, av. Pr. Angot, F-64053 Pau, France.
Anal Chim Acta. 2018 Aug 14;1018:7-15. doi: 10.1016/j.aca.2018.02.056. Epub 2018 Mar 5.
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.
镧系聚合物标记抗体被研究用于改善通过电感耦合等离子体质谱（ICP-MS）检测的均相免疫分析的分析性能，以用于人血清样品中多重生物标志物的分析。针对四种癌症生物标志物（CEA、sErbB2、CA15.3 和 CA125）的特异性单克隆抗体用不同的基于聚合物的镧系元素基团进行标记，以增加每个结合部位的金属标记数量。在生物标志物与特异性抗体发生免疫反应后，抗原-抗体复合物通过尺寸排阻色谱法分离，然后通过 ICP-MS 检测。聚合物标签可以负载比镧系元素 -DOTA 复合物多 30 倍的镧系元素原子，这导致灵敏度和检测限提高了 10 倍[1]。使用镧系聚合物标记策略获得的分析性能参数使在临床分析中使用的阈值参考值以下检测生物标志物成为可能。通过分析在三个不同浓度水平下用四种生物标志物加标过的对照人血清，成功验证了这种标记方法。对于所有研究的生物标志物，回收率范围在 95%到 110%之间，而批内和批间精密度低于 8%。使用这种方法获得的结果与基于电化学发光或 ELISA 检测的异质免疫分析获得的结果相当。然而，该方法使用更少的样品提供了更好的分析性能参数。
