10(6) DEPLETION OF WBC WITH CF-2, A NEW LEUKOCYTE REMOVAL FILTER

A new leukocyte removal filter, Nipro CF-2, was evaluated. A non-woven polyester filter, gravity flow device that does not require priming a nd rinsing after use was developed to remove white blood cells from 40 0 ml of whole blood or concentrates of 400 ml of whole blood. A flow c ytometric technique was developed to measure extremely low WBC counts. To evaluate the efficiency of this filter, leukocyte counts were meas ured by flow cytometry using a Coulter EPICS-C cytometer. After filtra tion through a CF-2 filter, more than 99.9999% of WBCs were depleted f rom 6 of 17 samples. The mean value of WBC depletion was 99.9994%. The CF-2 filter achieved nearly a million-fold depletion of WBCs from who le blood concentrates.