Melin J.,Amic A Wholly Owned Subsidiary of Johnson and Johnson Nordic |
Melin J.,Dublin City University |
Rundstrom G.,Amic A Wholly Owned Subsidiary of Johnson and Johnson Nordic |
Peterson C.,Amic A Wholly Owned Subsidiary of Johnson and Johnson Nordic |
And 7 more authors.
Analytical Biochemistry | Year: 2011
Several new plasma protein biomarkers have been associated with increased risk of cardiovascular events. It would be of great value if sets of these markers could be measured in a multiplexed format at point-of-care settings. A major challenge is the extremely wide concentration range in which different plasma biomarkers are present. Two promising biomarkers for cardiac risk prediction are C-reactive protein (CRP) and N-terminal pro-brain natriuretic peptide (NTproBNP). The concentrations of these markers can differ by more than six orders of magnitude. Here we present a chip-based multiplexed assay for CRP and NTproBNP. The high-concentration analyte, CRP, is analyzed in a competitive format, whereas the low-concentration analyte, NTproBNP, is analyzed in a sandwich format. This allows concurrent measurement of the two analytes in a single multiplexed assay. The dynamic ranges for the two assays were optimized to match the relevant serum concentration ranges; thus, no dilutions were needed. Both assays exhibit good precision (5-15% in the clinically relevant concentration ranges), and the limit of detection for the NTproBNP assay was 5 ng/L. Patient plasma samples were used for comparison with clinical methods, resulting in coefficients of determination (R2) of 0.9762 and 0.9606 for NTproBNP and CRP, respectively. © 2010 Elsevier Inc. All rights reserved.