The authors compared the efficiency of isolation and the purity of lymphocytes obtained by the method of centrifugation in a gradient of ficoll and uropoline from blood obtained on ACD fluid and on heparin. Isolation of lymphocytes from the blood obtained on heparin was more efficient (60%) and useful. For removal of platelets it was necessary to use additional centrifugation in a saccharose gradient or application of aggregating agents during isolation of lymphocytes obtained on heparin or ACD fluid.