porous membrane described above and collection and or detection of at least one cellular component u201c contacting u201d as used herein refers to establishing a physical contact between the biological sample and an area on the surface of the porous membrane of the invention u201c incubating u201d is used to describe contacting for a desired period of time collection comprises allowing at least one cellular component to be passed through the membrane u201c detection u201d refers to determining the amount of a particular cellular component collected on the other side of the membrane following lysis of a cell population the detection may be performed by means of assays known in the art including biochemical cellular chemical and electrochemical assays chemical reactions enzymatic reactions and binding interactions in an embodiment the organic polymeric compound used in step 010 a is cellulose acetate however in other embodiments other polymeric compounds such as for example cellulose ester fatty acid vinyl ester vinyl pyrrolidone ethylene oxide propylene oxide polysulfone and polystyrene may be used the surfactant in step 010 c may be selected from the group of sodium dodecyl sulphate generally known as sds cetyl trimethylammonium bromide generally known as ctab octyl phenol ethoxylate trade name triton x 100 polyethylene glycol tert octylpheny ether trade name triton x 114 the zwitterionic detergent generally known as chaps nonyl phenoxypolyethoxy ethanol commonly known as np 40 polysorbate 20 this group of surfactants is not exhaustive or restrictive but only representative other surfactants with different molecular structures derived from related to those of the aforesaid.