A microfluidic finger-actuated blood lysate preparation device enabled by rapid acoustofluidic mixing

Most blood-based assays, such as malaria tests or prophylactic drug analysis, require treating human red blood cells, which may involve removing, isolating, or lysing cells. Red blood cell lysis is necessary for therapeutic drug, such as tacrolimus, an immunosuppressive medication, have high affinity to red blood cells and require lysis prior to any downstream analytical procedure. Here we present a finger-actuated blood lysate preparation device, which incorporates our previously reported acoustofluidic micromixer module. A variety of innovations are included in the integrated device, including a handy blood collection device interface, on-chip reagent integration, allowing finger-actuated sample delivery, and a large volume (130 uL) manual pump which enables seamless and intuitive fluid movement into the chip. Integrated acoustic mixing is shown to be effective with highly viscous fluids, such as whole blood, which contains up to 65% volume fraction of red blood cells. Thanks to an effective microstreaming approach, our acoustofluidic mixing method enables gentle and lysis-free handling of human blood, or 30 second lysis when combined with a chemical buffer. Benchmarked across ten donor samples, we demonstrate this finger-actuated card to be an effective module for point-of-care blood sample preparation. We hope these highly modular functionalities could open the door to a variety of frugal diagnostics in limited resource settings.