A system for the sterile sequential treatment of biological fluid comprising: (a) a reusable cell processing apparatus comprising a separator element for receiving a separation device (101, 101') and effecting the separation of said biological fluid into two or more components, and a programmable microprocessor programmed to process biological fluid through a first disposable fluid circuit and a second disposable fluid circuit; (b) a first disposable fluid circuit comprising at least one separation device having an inlet port and at least two outlet ports (46, 48), wherein the separation device is via its inlet port in fluid communication with, an access site for sterile access to a treatment container of a wash fluid and an access device for sterile connection to a source container of biological fluid; and wherein the separation device is via its first outlet port in fluid communication with a waste container, and via its second outlet port in fluid communication with a first final product container; (c) a second disposable fluid circuit (100', 100", 100"') comprising at least one separation device (101', 101 ", 101'") having an inlet port (20', 20", 20'") and at least two outlet ports (46', 46", 46'"; 48', 48", 48"'), wherein the separation device (101', 101 ", 101"') is via its inlet port (20', 20", 20"') in fluid communication with an access site (134', 134", 134"') for sterile access to a treatment container of a wash fluid and an access device for sterile connection to a source container of a biological fluid (102', 102", 102'"); and wherein the separation device (101', 101 ", 101'") is via its first outlet port (46', 46", 46'") in fluid communication with a waste container (140', 140", 140"'), and via its second outlet port (48', 48", 48"') in fluid communication with a second final product container (150', 150", 150'"), wherein the separation device (101, 101') is a spinning membrane separation device, and wherein the separator element is a drive unit causing indirect driving of the spinning membrane separation device (101, 101'); wherein the first disposable fluid circuit further comprises an additional separation chamber for further processing of contents of the final product container, which chamber includes one or more ports (162, 164) for establishing fluid communication with the final product container, which additional separation chamber is disconnectable from the product container for transfer of contents thereof into the source container (102', 102", 102"') of the second disposable circuit (100', 100", 100"'). (a) a reusable cell processing apparatus comprising a separator element for receiving a separation device (101, 101') and effecting the separation of said biological fluid into two or more components, and a programmable microprocessor programmed to process biological fluid through a first disposable fluid circuit and a second disposable fluid circuit; (b) a first disposable fluid circuit comprising at least one separation device having an inlet port and at least two outlet ports (46, 48), wherein the separation device is via its inlet port in fluid communication with, an access site for sterile access to a treatment container of a wash fluid and an access device for sterile connection to a source container of biological fluid; and wherein the separation device is via its first outlet port in fluid communication with a waste container, and via its second outlet port in fluid communication with a first final product container; (c) a second disposable fluid circuit (100', 100", 100"') comprising at least one separation device (101', 101 ", 101'") having an inlet port (20', 20", 20'") and at least two outlet ports (46', 46", 46'"; 48', 48", 48"'), wherein the separation device (101', 101 ", 101"') is via its inlet port (20', 20", 20"') in fluid communication with an access site (134', 134", 134"') for sterile access to a treatment container of a wash fluid and an access device for sterile connection to a source container of a biological fluid (102', 102", 102'"); and wherein the separation device (101', 101 ", 101'") is via its first outlet port (46', 46", 46'") in fluid communication with a waste container (140', 140", 140"'), and via its second outlet port (48', 48", 48"') in fluid communication with a second final product container (150', 150", 150'"),