Following a French circular published in 2001, the use of glutaraldehyde for the disinfection of reusable medical devices was abandoned in favour of non-fixative disinfectants such as peracetic-acid-based solutions. Data published regarding the fixative properties of alternative disinfectants remain contradictory. We compared the effect of repetitive treatments of polytetrafluoroethylene (PTFE) tubes, contaminated by a liquid medium inoculated with Pseudomonas aeruginosa, using five different disinfectant solutions: two peracetic acid solutions (with and without an activator), glutaraldehyde, ortho-phthaldehyde and succine dialdehyde. The results confirmed that repeated treatments of a PTFE tube with a 2% glutaraldehyde solution induce an important accumulation and/or fixation of protein, compared to peracetic-acid-based disinfectants, for which the accumulation and/or fixation of proteins remain low and vary from one formulation to another.