Separation of human monocytes on density gradients of Percoll.

Monocytes from human blood have been isolated by centrifugation in Percoll. A one-step procedure has been designed to isolate the cells from 7 ml of blood. when 5% of the white blood cells are assumed to be monocytes, an estimated average yield of 100% and a purity of 20% is achieved. The contaminating cells are almost exclusively lymphocytes. By a two-step procedure the monocytes can be obtained 90% pure with an approximate yield of 35%. The cells can be used for tissue culture without washing and they display the usual properties of mononuclear phagocytes in vitro.