Simultaneous express immunoassay of multiple cardiac biomarkers with an automatic platform in human plasma

Abstract

C-reactive protein, cystatin C, myoglobin, and D-dimer represent the inflammatory or thromboembolic status of the patient and play important roles in early diagnostics of acute myocardial infarction. Each protein can indicate some health problems, but their simultaneous detection can be crucial for differential diagnostics. The express analysis of these proteins in a small drop of plasma was developed using magnetic beads. The suggested method is based on immunomagnetic extraction of the target analyte from plasma samples and its simultaneous labelling by fluorescent dye. Reaction time was optimized for quantification of cardiac biomarkers in the spike solutions and human plasma samples. In this paper, we developed a one-protein detection technique for each cardiac biomarker and united it to a four-protein facility using an automatic platform. The proposed technique requires only 17 μL of the human plasma and takes 14 min for four-protein measuring. The suggested technique covers concentration difference by more than two orders of magnitude and demonstrates analytical applicability by measurements of human plasma samples of 16 volunteers.

Keywords: Cardiac biomarkers; Fluorescent microscopy; Human plasma proteins; Immunoassay; Magnetic beads; Multiplex detection.