Patent ID: 7125493

Claim:
A blood separation device, the device comprising an asymmetric integral sulfone polymer membrane, the asymmetric membrane rendered hydrophilic through co-casting a sulfone polymer with a hydrophilic polymer, the asymmetric membrane comprising a first microporous skin surface, a porous support, and a second coarse pored surface, the microporous skin surface possessing skin pores, the skin pores having an average diameter of from about 0.1 micron to about 10 microns, the porous support comprising an asymmetric region of gradually increasing pore sizes, wherein pores on the second coarse pored surface have an average diameter of about 5 times to about 1000 times the diameter of the skin pores, wherein the device is capable of separating a first component of blood from a second component of blood based on a size difference between the first component and the second component.