Non-woven poly[ethylene terephthalate] (NW-PET) filter fabric, usually used for leucocyte removal of red cells, was modified by water vapour glow discharge (WVGD) treatment to improve platelet compatibility. Modified filter material was evaluated with different kinds of platelet concentrates (PCs). In addition, modified filter materials were gamma-sterilized and tested after different time intervals at different storage conditions. Modification of the filter material resulted in an improved platelet recovery after filtration of PC from 57 to about 80%. No significant difference in platelet recovery was observed when filtering either freshly prepared (79 +/- 3.5%, mean +/- SD), overnight-stored single BC-PC (78 +/- 3.3%), overnight-stored single PRP-PC (75 +/- 8.8%) or overnight-stored pooled BC-PC (79 +/- 8.9%). However, freshly prepared pooled BC-PC gave a significantly higher platelet recovery (84 +/- 3.5%). Leukocyte depletion did not differ significantly between the different types of PC. gamma-Sterilization and subsequent storage of the modified filter material for 5, 14 and 26 weeks at 20 degrees C or 37 degrees C had no significant influence on the filtration results of overnight-stored pooled BC-PC. The results of the present study show that WVGD-treated NW-PET is platelet compatible and can be used for leucocyte removal from preferably BC-PC. It can be gamma-sterilized and stored for at least 6 months prior to filtration without affecting the platelet recovery and leucocyte removal.