LAUSR

In this work, we demonstrate a multifunctional, portable, and disposable microfluidic device for blood typing and primary screen-ing of blood diseases. Preloaded antibodies (anti-A, anti-B, and anti-D) interact with injected whole blood cells to cause an agglu-tination reaction that blocks a microslit in the microfluidic channel to accumulate red blood cells and form a visible red line that can be easily read to determine the blood type. Moreover, the different blood density and agglutination properties of normal and subtype blood groups, as well as different blood diseases, including thalassemia and polycythemia vera, generate different lengths of blood agglutination within the channels, which allows us to successfully screen these various conditions in as little as 2 min. The required blood volume for each test is just 3 μL, which can be obtained by minimally invasive finger-pricking. This novel method of observing agglutinated red blood cells to distinguish blood type and disease is both feasible and affordable, suggesting its promise for use in areas with limited resources.