Authors: Filiz Ibraimi Dario Kriz Min Lu LarsOlof Hansson Kirstin Kriz
Publish Date: 2005/10/21
Volume: 384, Issue: 3, Pages: 651-657
Abstract
A rapid 55 min onestep whole blood C–reactive protein CRP magnetic permeability immunoassay utilizing monoclonal antibody conjugated dextran iron oxide nanoparticles 70 nm as superparamagnetic labels and mixed fractions 11 ratio of 15–40 and 60 μm of polyclonal antiCRP conjugated silica microparticles for enhanced sedimentation is described In this onestep assay procedure a whole blood sample 4 μl is applied to an assay glass vial containing both antibody conjugates and mixed for 30 s The target analyte CRP forms a sandwich complex between the conjugated nanoparticles and microparticles and subsequently the complex sediments under normal gravitation within 5 min to the bottom of the vial The magnetic permeability increase of the sediment due to the presence of the complexed superparamagnetic nanoparticles is determined using an inductancebased transducer Assayed patient whole blood samples were compared with the Abbott Diagnostics Architect reference method A strong linear correlation was observed for the CRP concentration range 0–260 mg/l in whole blood y=1001x+042 R 2=0982 n=50 The CRP assay presented showed a limit of detection of 3 mg/l and a total imprecision coefficient of variation of 105 On the basis of our observations we propose a rapid onestep CRP assay for nearpatient testing
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