Microfluidic chip designs and their application for E antigen typing on red blood cells.

The E antigen is one of the main Rh antigens on red blood cells (RBCs). The high ability of the E antigen to trigger an immune response along with the presence of anti-E, can cause serious issues such as hemolytic transfusion reactions and hemolytic disease in newborns. In this study, we developed a microfluidic biochip for Rh typing (E antigen). Three different micromixer types were compared for simulation, mixing tests, and optimal interactions of blood typing reagents and RBCs to provide an accurate agglutination reaction. Using separate syringe pumps, a blood sample and anti-E reagent were introduced into the microfluidic device through the respective inlet channels. Then, the fluids underwent thorough mixing within the micromixers before reaching reaction reservoirs where RBC agglutination was observed. The 8-shape micromixer design showed the most agglutination and indicated the best performance for E antigen detection and was able to differentiate blood clinical samples with E-positive and -negative RBCs. The microfluidic chip could also be applied for RBC antigen detection in blood bank procedures during blood typing and compatibility testing.