Lanthanide polymer labels for multiplexed determination of biomarkers in human serum samples by means of size exclusion chromatography-inductively coupled plasma mass spectrometry

Abstract

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.

Bimodal determination of immunoglobulin E by fluorometry and ICP-MS by using platinum nanoclusters as a label in an immunoassay

“…Within this context, single chelates [4], commercial polymers containing several lanthanide atoms covalently attached [5], metal nanoparticles (NPs) most commonly made of gold [6,7] with diameters in the order of 20-50 nm, and quantum dots (QDs) [8,9] have been successfully investigated as elemental labels. The use of labels with many atoms of a given metal per tag will allow high signal amplification, and thus, good sensitivity for detection of the corresponding biomolecule.…”

Evaluation of an Element-Tagged Duplex Immunoassay Coupled with Inductively Coupled Plasma Mass Spectrometry Detection: A Further Study for the Application of the New Assay in Clinical Laboratory

“…Compared with other immunoassays (ECLIA, FIA, CLIA, etc. ), the ICP-MS-based immunoassay has several unique advantages and the potential capability for multiplex analysis [22,23,34,35]. Although many studies have been reported for the ICP-MS-based immunoassay, these was no report of multiplex detection involve in standard evaluation and clinical sample detection with the guidance of CLSI documents [23].…”

“…The operation parameters of the ICP-MS analyzer are shown in Table 1. In order to eliminate the impact of some interference situations (such as salts and incomplete injection) on the test results, Rh 3+ , In 3+ , Tb 3+ , Ho 3+ and Re 3+ were selected as potential quality control elements according to previous reports [34]. In addition, the Eu-labeled CEA antibody and the Sm-labeled AFP antibody were tested 50 times to evaluate the imprecision (presented as relative standard deviation/coefficient of variation (CV)) of the analyzer.…”

Inductively Coupled Plasma Mass Spectrometry For Metrometallomics: The Study Of Quantitative Metalloproteins

“…These polymer tags bind up to 60~120 lanthanides per antibody and increased the final ICP-MS sensitivity. Perez et al 48 labeled specific monoclonal antibodies against four cancer biomarkers (CEA, sErbB2, CA 15.3 and CA 125) with different polymer-based lanthanides and separated, by size exclusion chromatography followed by ICP-MS detection, the antigen-antibody complex. The lanthanide loading in the polymer tag may be 30 times that of lanthanide-DOTA to improve the sensitivity and detection limit.…”