Separation of lymphocyte subsets by expanding velocity sedimentation of E-rosettes at unit gravity

An expanding velocity sedimentation procedure at unit gravity has been used to separate human lymphocyte subsets on the basis of E-rosette formation. It is shown that the method allows gentle yet efficient separation of T and non-T lymphocytes in a continuous gradient of colloidal silica (Percoll). Less efficient separation was obtained in gradients consisting of polymerized sucrose (Ficoll 70). The technique offers a special advantage in the possibility of separating lymphocytes binding differing numbers of indicator red cells. The method should be generally adaptable to various rosetting techniques, including systems where the indicator cells are attached with weak bonds. As judged by vital staining, the lymphocytes are in excellent condition after the separation.