Abstract: An object is to provide a blood processing filter favorable in both of the effectiveness (leukocyte removing performance) and the safety (reduction in the amount of elutable substances). The object can be achieved by a blood processing filter comprising a filtration medium including a polyester fiber, wherein a surface area of the filtration medium is 6.0 m2 or more, and a maximum absorbance of an aqueous extract of the blood processing filter in the range from 240 to 245 nm is 0.03 or less.

Abstract: There is disclosed a leukocyte removal filter material comprising a nonwoven fabric having polybutylene terephthalate fiber. The average fiber diameter of the nonwoven fabric is 0.9 to 1.5 ?m, the formation index corresponding to a thickness of 0.3 mm of the nonwoven fabric is 15 to 70, and when the average fiber diameter of the nonwoven fabric is X and the specific surface area of the nonwoven fabric is Y, X and Y satisfy the following relational expression (1): Y??0.65×X+1.75??(1).

Abstract: The present invention provides a filter element for a blood processing filter, comprising a nonwoven fabric, wherein the quantity of crystallization heat of the uncrystallized portion of the nonwoven fabric is 5 J/g or smaller before steam heat treatment.

Abstract: A filter element for a blood processing filter, containing a nonwoven fabric, wherein the nonwoven fabric has a carboxyl group equivalent of from 20 to 140 (?eq/g) and a surface ? potential of 0 mV or larger.

Abstract: In the removal of white blood cells from blood, the efficiency of white blood cell removal by a filter is improved. Centrifugal force is applied to blood placed in a blood bag by centrifugal separation to form a plurality of separation layers having a concentration gradient of white blood cells. The separation layers are passed through a filter in ascending order of white blood cell concentration to remove the white blood cells from the separation layers. The separation layers from which the white blood cells have been removed are received in a first blood component bag.

Abstract: The present invention provides a filter element for a blood processing filter, comprising a nonwoven fabric, wherein the rebound strength per unit basis weight (g/m2) before steam heat treatment is 0.3 (N·m2/g) or larger.

Abstract: The present invention provides a filter element for a blood processing filter, comprising a nonwoven fabric, wherein the quantity of crystallization heat of the uncrystallized portion of the nonwoven fabric is 5 J/g or smaller before steam heat treatment.

Abstract: There is disclosed a leukocyte removal filter material comprising a nonwoven fabric having polybutylene terephthalate fiber. The average fiber diameter of the nonwoven fabric is 0.9 to 1.5 ?m, the formation index corresponding to a thickness of 0.3 mm of the nonwoven fabric is 15 to 70, and when the average fiber diameter of the nonwoven fabric is X and the specific surface area of the nonwoven fabric is Y, X and Y satisfy the following relational expression (1): Y??0.65×X+1.75 ??(1).

Abstract: In the removal of white blood cells from blood, the efficiency of white blood cell removal by a filter is improved. Centrifugal force is applied to blood placed in a blood bag by centrifugal separation to form a plurality of separation layers having a concentration gradient of white blood cells. The separation layers are passed through a filter in ascending order of white blood cell concentration to remove the white blood cells from the separation layers. The separation layers from which the white blood cells have been removed are received in a first blood component bag.

Abstract: In the removal of white blood cells from blood, the efficiency of white blood cell removal by a filter is improved. Centrifugal force is applied to blood placed in a blood bag by centrifugal separation to form a plurality of separation layers having a concentration gradient of white blood cells. The separation layers are passed through a filter in ascending order of white blood cell concentration to remove the white blood cells from the separation layers. The separation layers from which the white blood cells have been removed are received in a first blood component bag.

Abstract: In the removal of white blood cells from blood, the efficiency of white blood cell removal by a filter is improved. Centrifugal force is applied to blood placed in a blood bag by centrifugal separation to form a plurality of separation layers having a concentration gradient of white blood cells. The separation layers are passed through a filter in ascending order of white blood cell concentration to remove the white blood cells from the separation layers. The separation layers from which the white blood cells have been removed are received in a first blood component bag.

Abstract: In the removal of white blood cells from blood, the efficiency of white blood cell removal by a filter is improved. Centrifugal force is applied to blood placed in a blood bag by centrifugal separation to form a plurality of separation layers having a concentration gradient of white blood cells. The separation layers are passed through a filter in ascending order of white blood cell concentration to remove the white blood cells from the separation layers. The separation layers from which the white blood cells have been removed are received in a first blood component bag.