The Isopaque–Ficoll Method Re‐evaluated: Selective Loss of Autologous Rosette‐forming Lymphocytes during Isolation of Mononuclear Cells from Human Peripheral Blood

Abstract

A subpopulation of lymphocytes was defined, which, under conditions used for isolating mononuclear cells from peripheral blood by the Isopaque-Ficoll gradient, is lost to the erythrocyte pellet because of rosette formation with the autologous erythrocytes in the gradient. Reapplication of the resuspended erythrocyte pellet on a new gradient with higher density could recover the subpopulation. Lympocyte surface marker analysis on such cells showed that they were enriched in T [thymus-derived] cells (judged by rosette formation with sheep erythrocytes) and in auto-rosette-forming cells. The importance of these findings was discussed in relation to the wide use of the Isopaque-Ficoll method.