The invention, is directed to devices and methods for low cost and convenient separation, of plasma from whole blood. In some embodiments, devices of the invention comprise an integrated collection of channels and chambers m a body that permit acquisition of a blood sample by capillary action, centrifugal separation of cells from plasma, and manual dispensing of purified plasma by simple pinching of a bellows chamber to force air into plasma-holding channels which thereby expels a predetermined volume of the purified plasma.