RESUMO
BACKGROUND AND OBJECTIVES: Solid phase microarrays have been described for use in blood typing; red blood cells (RBCs) captured on immobilized antibodies were detected using surface plasmon resonance or fluorescence. We present antibody microarray on Poly (methylmethacrylate) (PMMA) surface coupled with microfluidic system for ABO and RhD blood typing. After immobilized by antigen-antibody interaction, the RBCs were detected by image recognition. MATERIALS AND METHODS: The sensor surface was produced from grafted aminopropyltriethoxysilane (APTES) on photochemical modified PMMA surface by UV irradiation and subsequently reacted with glutaraldehyde cross-linking. The amine group of monoclonal antibody of anti-A, anti-B and anti-D was reacted with an aldehyde group on the glutaraldehyde modified surface, forming an imine linkage. RBCs were captured by the coated antibody via antigen-antibody interaction, and blood grouping was determined by microarray image cell counting. RESULTS: Suitable condition for RBC detection was 10% RBC concentration at 10 µl/min flow rate. This setting eliminated non-specific RBC binding resulting in correct blood groups identification of all 136 samples tested. The platform showed good reproducibility with coefficient of variation of 2·17%, 3·62% and 2·51% for anti-A, anti-B and anti-D respectively. The antibody-coated surface can be stabilized by stabilizer coating and stored for long-term use. CONCLUSION: The PMMA array chip demonstrated its good accuracy and precision in rapid blood group testing. For its high throughput, the method has potential for use in large blood donation centre.