Method of separating cells from blood using a filter having a changeable porosity

Abstract

A method of separating cells from blood by using a filter apparatus having first and second ports and a filter member therebetween having a changeable porosity. The filter member includes a stack of porous polymer sheets that preferably has a gradient of a physical or chemical characteristic in the direction of stacking. This can include a gradient in porosity, hydrophilicity or zeta potential. In a first step, blood is filtered through the apparatus when the filter member is set to a compressive state having a first porosity capable of capturing the objective cells. In a later step, the filter member is then set to a non-compressive state having a second porosity, higher than the first, for recovering the objective cells. The change in porosity results from the enlargement or reduction of the diameter of the pores of the filter member. The method can also include washing the filter member when the member is set to a porosity that is higher than the first porosity but lower than the second porosity.

Dependencies are inferred from the claim text.