Abstract: It is intended to provide a method whereby a virus and leukocytes can be simultaneously eliminated from virus-containing blood and platelets can be recovered at a high yield, and a material and an apparatus therefor. A water-soluble carrier having surface which is capable of capturing a virus and leukocytes in blood but allows the permeation of platelets therethrough is brought into contact with virus-containing blood. Thus the virus and leukocytes can be simultaneously removed from the blood while platelets can be recovered at a high yield.

Abstract: It is intended to provide a polymer which is scarcely eluted, has a high biocompatibility and is useful in a filter for selectively eliminating leucocytes. It is also intended to provide a filter for selectively eliminating leucocytes, a filtration apparatus for selectively eliminating leucocytes and a system for selectively eliminating leucocytes, each having the above-described polymer. The above objects can be achieved by providing a polymer which comprises from 8% by mol to 45% by mol of a unit originating in a polymerizable monomer having a polyalkylene oxide chain, from 30% by mol to 90% by mol of a unit originating in a polymerizable monomer having a hydrophobic group, and from 2% by mol to 50% by mol of a unit originating in polymerizable monomer having a hydroxyl group.

Abstract: It is intended to provide a method whereby a virus and leukocytes can be simultaneously eliminated from virus-containing blood and platelets can be recovered at a high yield, and a material and an apparatus therefor. A water-soluble carrier having surface which is capable of capturing a virus and leukocytes in blood but allows the permeation of platelets therethrough is brought into contact with virus-containing blood. Thus the virus and leukocytes can be simultaneously removed from the blood while platelets can be recovered at a high yield.

Abstract: It is intended to provide a polymer which is scarcely eluted, has a high biocompatibility and is useful in a filter for selectively eliminating leucocytes. It is also intended to provide a filter for selectively eliminating leucocytes, a filtration apparatus for selectively eliminating leucocytes and a system for selectively eliminating leucocytes, each having the above-described polymer. The above objects can be achieved by providing a polymer which comprises from 8% by mol to 45% by mol of a unit originating in a polymerizable monomer having a polyalkylene oxide chain, from 30% by mol to 90% by mol of a unit originating in a polymerizable monomer having a hydrophobic group, and from 2% by mol to 50% by mol of a unit originating in polymerizable monomer having a hydroxyl group.

Abstract: It is intended to provide a method whereby a virus and leukocytes can be simultaneously eliminated from virus-containing blood and platelets can be recovered at a high yield, and a material and an apparatus therefor. A water-soluble carrier having surface which is capable of capturing a virus and leukocytes in blood but allows the permeation of platelets therethrough is brought into contact with virus-containing blood. Thus the virus and leukocytes can be simultaneously removed from the blood while platelets can be recovered at a high yield.

Abstract: A leukocyte-removing material composed substantially of a polyolefin, the factor of hydrophilicity of the surface of said leukocyte-removing material being less than 40% and not less than 30%.

Abstract: A material comprising a biologically active substance (or ligand) to be sterilized, including proteins (e.g., antibodies and enzymes), peptides, DNA, RNA, and glycoproteins, with or without a carrier, and sterilization-protecting agent comprising a trisaccharide or higher saccharide (“polysaccharide”) having a positive charge, is provided. The skeletal background of the polysaccharide confers stability to the ligand and its positive charge traps destructive radicals produced during the sterilization process. The molecular weight ratio of sterilization-protecting agent to the ligand should be at least {fraction (1/500)} but less than ½ to protect the ligand effectively without obstructing the ligand's activity. In particular, polysaccharides, such as chitosan (a polymer of D-glucosamine) and chitin which is partially converted into chitosan, are preferable as a sterilization-protecting agent.

Abstract: A material comprising a to-be-sterilized material and a sterilization-protecting agent comprising a trisaccharide or higher saccharide having a positive charge(s).

Abstract: Disclosed is a filter medium for treating a blood material selected from the group consisting of a leukocyte-containing suspension and plasma, comprising a polymeric, porous element having, in a surface portion thereof, a negative charge and having a surface electric charge of not smaller than -30 .mu.eq/g of the polymeric, porous element. The filter medium and an apparatus having the filter medium packed in a casing having an inlet and an outlet, can be advantageously used for treating a blood material, for example, for separating leukocytes from a leukocyte-containing suspension including whole blood, for blood dialysis or for removing undesired proteinous substances and the like from whole blood or plasma by adsorption-filtration, while effectively controlling a concentration of bradykinin (which is causative of anaphylactic reactions) in a treated blood to a level not exceeding 4,000 pg/ml.