title: ABO, D blood typing and subtyping using plug-based microfluidics.
abstract: A plug-based microfluidic approach was used to perform multiple agglutination assays in parallel without cross-contamination and using only microliter volumes of blood. To perform agglutination assays on-chip, a microfluidic device was designed to combine aqueous streams of antibody, buffer, and red blood cells (RBCs) to form droplets 30-40 nL in volume surrounded by a fluorinated carrier fluid. Using this approach, proof-of-concept ABO and D (Rh) blood typing and group A subtyping were successfully performed by screening against multiple antigens without cross-contamination. On-chip subtyping distinguished common A1 and A2 RBCs by using a lectin-based dilution assay. This flexible platform was extended to differentiate rare, weakly agglutinating RBCs of A subtypes by analyzing agglutination avidity as a function of shear rate. Quantitative analysis of changes in contrast within plugs revealed subtleties in agglutination kinetics and enabled characterization of agglutination of rare blood subtypes. Finally, this platform was used to detect bacteria, demonstrating the potential usefulness of this assay in detecting sepsis and the potential for applications in agglutination-based viral detection. The speed, control, and minimal sample consumption provided by this technology present an advance for point of care applications, blood typing of newborns, and general blood assays in small model organisms.
authors.affiliation: Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Kline
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Runyon
authors.forename: Mohammad
authors.initials: M
authors.lastname: Pothiawala
authors.forename: Rustem F
authors.initials: RF
authors.lastname: Ismagilov
mesh_terms: D000017:ABO Blood-Group System / Q000097:blood*; D000937:Antigen-Antibody Reactions; D001788:Blood Grouping and Crossmatching / Q000295:instrumentation / Q000379:methods*; D004906:Erythrocyte Count; D004910:Erythrocyte Membrane / Q000276:immunology; D006386:Hemagglutination Tests; D006801:Humans; D046228:Microarray Analysis / Q000295:instrumentation / Q000379:methods; D044085:Microfluidics / Q000295:instrumentation / Q000379:methods*; D012204:Rh-Hr Blood-Group System / Q000097:blood*; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000276:immunology*
chemical_list: D000017:ABO Blood-Group System; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen