Professor Je-Kyun Park’s research team reported a finger-actuated microfluidic display for smart blood typing that directly displays whether a person has an A, B, AB, or O blood type, and whether the person is Rh positive or negative. The device is quick and easy to operate by repeatedly pushing a button on the device.
Blood typing is used as the first-line pretransfusion suitability test. Inaccurate blood typing of donor and recipient can result in a hemolytic transfusion reaction in a recipient. Simple blood typing has been performed by analyzing the agglutination patterns in the reaction between individual blood-typing reagents, but it can lead to human-induced error in the interpretation of agglutination patterns. To prevent this, fully automated blood-typing systems are used in blood banks and hospitals. Although these yield reliable results, they are not suitable for rapid blood typing of patients in urgent need of transfusion.
In this project, a simple and rapid blood-typing system was developed using a finger-actuated microfluidic device that displays the blood type by means of microfluidic channels. With use of a novel working principle of a finger-actuated microfluidic pump, the device demonstrates constant performance regardless of differences in end users. The device also allows parallel mixing of blood and reagents with a predesigned ratio. According to the agglutination patterns in each mixture, the fluidic paths are determined adaptively. By means of microfluidic channels, the determined fluidic paths present the results of the blood typing with letters. The blood type of an unknown sample can be determined simply by pushing the button within 30 s and using less than 10 μL of blood. It is notable that human-induced error during the manual interpretation of results can be prevented. Although it is demonstrated for the most common blood types (Rh and ABO), the system can be expanded to minor human blood-type systems (e.g. the Kell, Kidd, MNS, and Lewis systems).