[Filtration technology].

The leukocyte removal technology of platelet and red blood cell concentrates is now based on the only method: the filtration. In order to perfectly control this technology, it is necessary to know the different parameters that interfere in the quality of the leukocyte removal. These different parameters are studied here. They are classified in two types: the parameters that are related to the concentrate to filtrate: method used for the preparation, age, state (temperature, aggregates), concentration of red blood cells, platelets and leukocytes; the parameters that are related to the leukocyte removal technology and to the different steps of its carrying out: filter type (composition, size, geometry), prefilter, priming of the filter, flow rate during the filtration, rinsing and centrifugation after the filtration, elimination of the air inside the filter and the filtered concentrate, sterile connections, and finally good behavior in front of the difficulties and hitchs that could occur during the filtration procedure.