A plasma separator with a multifunctional deformable chamber equipped with a porous membrane for point-of-care diagnostics

Traditionally, plasma is extracted from whole blood using centrifuges in clinical laboratories, which is unsuitable for on-site testing. For point-of-care diagnostics, for example in HIV tests, to ensure the detection sensitivity for low-abundance analytical targets, a relatively large volume of plasma needs to be extracted from milliliters of blood with a simpler and easier-to-operate method than centrifugation. We report the development of a membrane-assisted, sedimentation-facilitated plasma separator with a multifunctional deformable chamber, which is able to perform plasma separation from undiluted whole blood in a short time. Multiple steps related to plasma separation, including cell sedimentation, cell filtration, and plasma driving and discharging, are all performed in or through the multifunctional deformable chamber equipped with a top-layer porous membrane, which significantly reduces the device complexity. Assisted by a simple jig or even hands, plasma separation can be conveniently performed upon mechanical actuation of the deformable chamber. Within 8 min, similar to 130 mu L of plasma can be conveniently extracted with the described device from 2.3 mL of whole blood. It has been demonstrated that HIV antibodies or virus spiked in whole blood can be successfully detected with reasonable sensitivity from the extracted plasma with the described pump-free device.