A method for the separation of lymphocytes and plasma cells from the human palatine tonsil using sedimentation in an isokinetic gradient of Ficoll in tissue culture medium.

Several methods for the dissociation of human tonsils into cell suspensions were compared. Dissociation of tonsils using 0-25 per cent trypsin gave both the largest number of total cells and the largest number of plasma cells per gram of tonsil. Lymphocytes and plasma cells were separated in a previously described isokinetic gradient of Ficoll in tissue culture medium. In the purest gradient fractions, lymphocytes were 97-2 plus or minus 1-9 per cent of nucleated cells. The purest gradient fractions contained 43-1 plus or minus 5-9 per cent plasma cells. More than 95 per cent of purified lymphocytes and plasma cells excluded Trypan Blue.