Human granulocyte isolation by continuous flow centrifugation leukapheresis and counterflow centrifugation elutriation (CFCL/CCE).

Human granulocytes (PMNL) isolated by continuous flow centrifugation leukapheresis (CFCL) were further purified by counterflow centrifugation elutriation (CCE). Studies were conducted to determine the maximal granulocyte capacity of the 4.5-ml elutriation chamber and to determine the efficiency of granulocyte recovery from CFCL concentrates. The maximal capacity of the elutriation chamber was determined to be 1.30 x 10(9) granulocytes with a 98.8 percent granulocyte purity and a 51:1 PMNL/RBC ratio. The efficiency of recovery was 82.2 percent with a 95.1 percent granulocyte purity and a 68:1 PMNL/RBC ratio. The CCE flow system was designed to allow continuous elutriation runs without need of breakdown time between runs. In four to five hours, approximately 4 to 5 x 10(9) granulocytes can be isolated with purity in excess of 95 percent. In vitro analysis of the viability and function of CFCL/CCE-isolated granulocytes indicates that the morphologic integrity and physiologic function were not comprised as a result of the combined isolation procedure relative to granulocytes isolated by CCE from whole blood samples. Granulocytes were held at 4 to 6 C for 16 to 24 hours in granulocyte storage medium (GSM) plus 20 percent autologous plasma at concentrations of about 6 x 10(6) PMNL/ml prior to in vitro analysis.