Leukocyte trapping apparatus

A leukocyte trapping apparatus comprising:

• a chip for passing a blood-containing liquid therethrough and trapping leukocytes contained in the blood-containing liquid,
• wherein the chip has a flat part and a first plurality of protruding parts provided thereon, and is configured so that the blood-containing liquid having entered through an inlet passes on a surface of the flat part in the chip, and through spaces each located between a protruding part and another protruding part adjacent thereto and is discharged from an outlet,
• wherein the first plurality of protruding parts is provided on the flat part and forms a plurality of layers, each layer has a second plurality of protruding parts that is a subset of the first plurality of protruding parts, and the first plurality of protruding parts is configured so that the blood-containing liquid having passed through a layer on an inlet side passes through a another layer adjacent thereto on an outlet side,
• wherein, in a direction perpendicular to the flat part of the chip, each protruding part of the first plurality of protruding parts has a generally rectangular shape in which part of edges in four corners are linearly cut off to be a chamfered portion,
• wherein, in a direction parallel to the flat part of the chip, a surface of each protruding part of the first plurality of protruding parts has a pentagonal shape,
• wherein trapping parts and bypass parts are formed in each layer, each of the trapping parts having a width set to 2 to 7.5 μm between the protruding part and the another protruding part adjacent thereto, and each of the bypass parts having a width set to 8 to 20 μm therebetween,
• wherein the chamfered portion is made so that a width between inlet side portions on the inlet side of two protruding parts constituting one trapping part is gradually reduced toward a bottom of the trapping part, and
• wherein the trapping parts are disposed so as to face the outlet side of all or some of the bypass parts in a specific layer as part of another layer adjacent thereto.