Immune-stimulating microbiological components like lipopolysaccharide (LPS), lipoteichoic acid (LTA) and zymosan bound onto surfaces lead to severe problems when brought in contact with the organism via surgical instruments or implants. We have shown in recent studies that it is possible to detect different immune-stimulating components directly on the surface, via the human whole blood model, which uses the monocyte reactions to measure the inflammatory mediator release (IL-1β) by ELISA. With regard to the inactivation of pyrogenic substances, we present a method based on the application of a low-pressure microwave plasma discharge working at low temperatures. We found a fast (10 s to a few minutes) removal rate for LPS, LTA and zymosan. To mimic the bacterial cell-wall, LPS in combination with muramyl dipeptide (MDP) was employed and the removal rate did not differ from pure LPS. In conclusion, we found that the human whole blood incubation test is a very sensitive method to detect residues of immune-stimulating components directly on the surface, without the problem of preparing eluates and related losses on the surface. Furthermore, we found that the low-pressure microwave discharge plasma is an appropriate method to eliminate various immune-stimulating components relatively fast, under low-temperature conditions preventing treated substrates from the heat-induced modifications and without necessity to use toxic compounds. This was demonstrated first for LPS, the most potent immune-stimulatory component that can be removed in a reliable way and with fast kinetics, even if the signal is synergistically increased by another substance. Gram-positive stimuli, which are gaining more and more importance, could be removed as well with a very fast removal rate. Also zymosan, as a well-introduced monocyte and macrophage stimulus, was removable to major extent. ; JRC.I.2-Validation of biomedical testing methods