Univ. Grenoble Alpes, CEA LETI MlNATEC Campus, Grenoble, France, Univ. Grenoble Alpes, INAC-SPRAM, Grenoble, France, CEA, INAC-SPRAM, Grenoble, France, CNRS, INAC-SPRAM, Grenoble, France

The process of agglutination is commonly used for the detection of biomarkers like proteins or viruses. The multiple bindings between micrometer sized particles, either latex beads or red blood cells (RBCs), create aggregates that are easily detectable and give qualitative information about the presence of the biomarkers. In most cases, the detection is made by simple naked-eye observation of agglutinates without any access to the kinetics of agglutination. In this study, we address the development of a real-time time observation of RBCs agglutination. Using ABO blood typing as a proof-of-concept, we developed i) an integrated biological protocol suitable for further use as point-of-care (POC) analysis and ii) two dedicated image processing algorithms for the real-time and quantitative measurement of agglutination. Anti-A or anti-B typing reagents were dried inside the microchannel of a passive microfluidic chip designed to enhance capillary flow. A blood drop deposit at the tip of the biochip established a simple biological protocol. In situ agglutination of autologous RBCs was achieved by means of embedded reagents and real time agglutination process was monitored by video recording. Using a training set of 24 experiments, two real-time indicators based on correlation and variance of gray levels were optimized and then further confirmed on a validation set. 100% correct discrimination between positive and negative agglutinations was performed within less than 2 min by measuring real-time evolution of both correlation and variance indicators. © 2016 Elsevier B.V.

ABO blood typing, Agglutination assay, Automated image processing, Embedded reagents, Passive microfluidic, Real time detection

Antigen-antibody reactions, Bacteria, Bioassay, Biochips, Bioinformatics, Biology, Biomarkers, Blood, Microarrays, Microfluidics, Video recording, Viruses, Automated image processing, Blood typing, Embedded reagents, Image processing algorithm, Micrometer sized particles, Qualitative information, Quantitative measurement, Real-time detection, Image processing, Article, biochip, blood group ABO system, blood group typing, capillary flow, cell agglutination, controlled study, erythrocyte, hemagglutination test, human, hydrophilicity, image processing, microfluidics, point of care testing, process optimization, sensitivity and specificity, validation process, wettability, antigen antibody reaction, chemistry, erythrocyte, genetic procedures, immunology, microfluidics, procedures, antibody, Agglutination, Antibodies, Biosensing Techniques, Blood Grouping and Crossmatching, Erythrocytes, Humans, Microfluidics