Lymphocyte purification from normal human peripheral blood by filtration through columns of cotton wool.

With a view to simplifying the separation of haemopoietic stem cell concentrates from human peripheral blood, in preparation for their clinical use, the production of lymphocyte concentrates by cotton wool filtration has been investigated. Using the method which is described in detail, highly purified suspensions may be prepared without the selective loss of thymus-independent lymphocytes. Optimal operating conditions are defined. Haemopoietic stem cell concentrates may thereby be harvested, and are shown to be capable of proliferation and differentiation on subsequent culture in vivo.