B-031 Digital Elisatotal 25-Hydroxyvitamin D

Abstract Evaluation of digital ELISA using a high-resolution computational optical system for measurement total 25-hydroxyvitamin D Background Biomarkers such as vitamin occur at very low concentrations in blood, and sensitive detection methods are required order to measure them. It is difficult accurately low-concentration biomarkers conventional enzyme-linked immunosorbent assays (ELISA) with fluorescence staining. By developing (DELISA, Small Machines, Seoul, Korea) platform, concentration substance was realized by analyzing the digitalized signal through microfluidic chip. We evaluated DELISA (25OHD) fluidic Methods The sample monoclonal antibody bead conjugates mixture incubated 20 min 37°C, then 30 uL applied inlet After additional incubation 2 room temperature after application, 120 washing buffer onto hole chip 10 min. 25OHD molecules bond magnetic beads coupled anti-25OHD end membrane. Chips were inserted into DELISA, results derived analysis method microscopic imaging, proportional 25OHD. Assay performance characteristics limit (LoD), precision analytical interval (AMI) Vitamin Depleted, Low High Serum (Molecular Depot, San Diego, CA) determined according Clinical Laboratory Standards Institute (CLSI) guidelines. 87 Samples comparison studies obtained from routine clinical samples submitted OHD determination or apparently healthy normal volunteers. study approved Institutional Review Board Dongguk University Ilsan Hospital (202207024). Results LoD 10.3 ng/mL within-laboratory 11, 12, 10% coefficient variation 14.1, 56.6, 113.2 ng/mL, respectively. best fit polynomial cubic equation 14.1 difference between third-order first-order Level 3 4 outside non-linearity limit. Comparison chemiluminescent assay (Elecsys II, Roche Diagnostics, Mannheim, Germany) yielded 0.904 correlation 0.921 slope range 7.0 57.9 ng/mL. Conclusions has suitable precision, however, it necessary improve AMI high values automated analyzer.