Abstract: A flexible blood filter allowing smooth flow of a liquid and being excellent in separation resistance, pressure resistance and centrifugation resistance. The blood processing filter, comprising a first filter element for removing aggregates from blood, a second filter element for removing leukocytes provided in the downstream of the first filter element, and the third filter element having gas permeability of 3 to 40 cc/cm2/sec per thickness of 1 cm provided between the second filter element and the outlet port side container.

Abstract: A flexible blood filter allowing smooth flow of a liquid and being excellent in separation resistance, pressure resistance and centrifugation resistance. The blood processing filter, comprising a first filter element for removing aggregates from blood, a second filter element for removing leukocytes provided in the downstream of the first filter element, and the third filter element having gas permeability of 3 to 40 cc/cm2/sec per thickness of 1 cm provided between the second filter element and the outlet port side container.

Abstract: A flexible blood filter allowing smooth flow of a liquid and being excellent in separation resistance, pressure resistance and centrifugation resistance. The blood processing filter, includes a first filter element for removing aggregates from blood, a second filter element for removing leukocytes provided in the downstream of the first filter element, and a third filter element having gas permeability of 3 to 40 cc/cm2/sec per thickness of 1 cm provided between the second filter element and the outlet port. The filter contains a seal zone at a peripheral section which contains five layers including a layer of molten material and layers of molten material mixed with filter element material.

Abstract: A flexible blood filter allowing smooth flow of a liquid and being excellent in separation resistance, pressure resistance and centrifugation resistance. The blood processing filter, includes a first filter element for removing aggregates from blood, a second filter element for removing leukocytes provided in the downstream of the first filter element, and a third filter element having gas permeability of 3 to 40 cc/cm2/sec per thickness of 1 cm provided between the second filter element and the outlet port.

Abstract: A blood collection system has a container for holding blood and a filter communicating with the container, mutually arranged for handling as a unit. The filter (20) contains a fibrous filter medium (28) housed within two flexible sheets (32, 34) of plastic. A first seal (36) joins the sheets (32, 34) directly to the filter medium (28) inboard of the peripheral edge (40) of the filter medium (28), and a second seal (38) joins the sheets (32, 34) outboard of the peripheral edge (40) of the filter medium (28). A region (42) of the filter medium (28) extends between the first and second seals (36, 38) to cushion contact with the filter housing during handling.

Abstract: A method for removing leukocytes from a leukocyte-containing blood product, include subjecting a leukocyte-containing blood product to a first stage leukocyte-removing treatment to remove at least 60% of all leukocytes contained in the leukocyte-containing blood product, thereby obtaining a leukocyte-depleted blood product, and passing the leukocyte-depleted blood product through a microfilter element to perform a second stage leukocyte-removing treatment, the microfilter element having a non-woven or a woven fabric including fibers having an average diameter of from 0.3 to 1.6 .mu.m. A filter system for removing leukocytes from a leukocyte-containing blood product, to includes a first filter element for the first stage and a second filter element for the second stage, wherein the first filter element communicates with the second filter element and is positioned upstream of the second filter element with respect to a direction in which a leukocyte-containing blood product is to be flowed.