In this project we will push the limits of microscale ultrasound-based technology to gain access to diagnostically important rare constituents of blood within minutes from blood draw. To meet the demands for shorter time from sampling to result in healthcare there is an increased interest to shift from heavy centralized lab equipment to point-of-care tests and patient self-testing. Key challenges with point-of-care equipment is to enable simultaneous measurement of many parameters at a reasonable cost and size of equipment. Therefore, microscale technologies that can take in small amounts of blood and output results within minutes are sought for. In addition, the high precision and potential for multi-stage serial processing offered by such microfluidic methods opens up for fast and automated isolation of rare cell populations, such as circulating tumor cells, and controlled high-throughput size fractionation of sub-micron biological particles, such as platelets, pathogens and extracellular vesicles. To achieve effective and fast separation of blood components we will expose blood to acoustic radiation forces in a flow-through format. By exploiting a newly discovered acoustic body force, that stems from local variations the acoustic properties of the cell suspension, we can generate self-organizing configurations of the blood cells. We will tailor and tune the acoustic cell-organization in novel ways by time modulation of the acoustic field, by altering the acoustic properties of the fluid by solute molecules, and by exploiting a novel concept of sound interaction with thermal gradients. The project will render new fundamental knowledge regarding the acoustic properties of single cells and an extensive theoretical framework for the response of cells in any aqueous medium, bounding geometry and sound field, potentially leading to new diagnostic methods.