Principles of Blood Separation and Component Extraction in a Disposable Continuous‐Flow Single‐Stage Channel

Guest Editor's Introduction: By 1977, the NCI/IBM 2990 and the Amico Celltrifuge, a conceptually similar instrument that had an identical centrifuge bowl, were being used worldwide. However, a major technical problem remained in that the blood path was still not completely disposable. To overcome this drawback, IBM 2977 was developed. The centrifuge bowl was changed from an axial flow separator to a circumferential flow geometry. The IBM 2997 single-stage channel instrument was first introduced and followed by the dual-stage channel instrument to obtain platelet concentrate with minimum lymphocyte contamination. This paper describes the basic design, operation conditions, and collection performance of the single-stage channel IBM 2977. This paper was printed in Blood, vol 54, page 254–268 (1979) and reprinted here with permission. A single-stage disposable channel and seal that provides for leukocyte and granulocyte collection by continuous-flow cell separation (CFCS) has been designed by the IBM Corporation. This paper describes (1) the separation characteristics of whole blood as it responds to varying gravitational (G) forces and flow rates through the channel; (2) the mechanism by which the buffy coat accumulates and is extracted; (3) the efficiency of extraction; (4) those donor and procedural variables that contribute to the final yield; (5) posttransfusion increment response in patients; and (6) the functional integrity of the cells collected.