Systems and methods for the washing and processing of biological fluid/biological cells are disclosed. The systems and methods utilize a disposable fluid circuit including a spinning membrane separation device to wash the biological cells.

A blood bag system includes: a first bag in which blood containing multiple components is stored; a second bag in which a relative medium-density component is stored; a third bag in which a relative low-density component is stored; a first tube through which the relative low-density component and the relative medium-density component are transported from the first bag to the second bag; and a second tube through which the relative low-density component is transported from the first bag to the third bag. A blood treatment method involves: centrifuging blood containing multiple components in a first bag, transporting a low-density component from the first bag to a third bag through a first tube and transporting a relative medium-density component from the first bag to the second bag through the first tube.

A blood bag system includes: a first bag in which blood containing multiple components is stored; a second bag in which a relative medium-density component is stored; a third bag in which a relative low-density component is stored; a first tube through which the relative low-density component and the relative medium-density component are transported from the first bag to the second bag; and a second tube through which the relative low-density component is transported from the first bag to the third bag. A blood treatment method involves: centrifuging blood containing multiple components in a first bag, transporting a low-density component from the first bag to a third bag through a first tube and transporting a relative medium-density component from the first bag to the second bag through the first tube.

A method for in-line sampling for a medical device includes prompting an operator of a medical device to establish a fluid communication between a fluid component collection set as received by the medical device and a sample system for sample collection, where the medical device prohibits removal of the fluid component collection set or a component thereof from fluid communication with the medical device until sample collection using the sample system is complete and the establishing of fluid communication between the fluid component collection set includes prompting the medical device to interpret a code disposed on an exterior-facing surface of the sample tube.

A blood component sampling cassette which can be more efficiently manufactured at lower cost as compared to a typical cassette, a blood sampling circuit set, and a blood component sampling system. A blood component sampling cassette (22) includes a cassette main body (23) made of a soft material to which heat sterilization is applicable. The cassette main body (23) is provided with a retransfusion line (44). The retransfusion line (44) is provided with a reservoir (47) configured to temporarily store a blood component to be returned to a blood donor. The reservoir (47) is pressed by a retransfusion pump (49) to discharge the blood component from the reservoir (47).