SEPARATION OF MAMMALIAN CELLS USING PROGRAMMED GRADIENT SEDIMENTATION

A method is described for the sterile separation of viable, mammalian cells on density gradients of Ficoll in tissue culture medium. The gradients are contained in cylindrical tubes which are centrifuged at low speed at 4.0°C. A computer program is described which permits the rapid determination (during an experiment) of the optimal conditions (Ficoll concentration, gradient slope, and speed and duration of centrifugation) for obtaining the widest possible separation of cell types. The described method theoretically permits separation of cells which differ from each other by as little as one micron in diameter or 0.010 gm/ml in density. Experimental verification of the computer predicted cell sedimentation behavior is presented. © 1969.