**ISO 10993, Part 5: Tests for Cytotoxicity-**

HA coated PEEK and coated PEEK that had the coating removed, were prepared using single strength Miminum Essential Medium supplemented with 5% serum and 2% antibiotics (1X MEM). The test extracts were placed onto three separate monolayers of L-929 mouse fibroblast cells propagated in 5% CO2. Three separate monolayers were prepared for the reagent control, negative control and for the posititve control. All monolayers were incubated at 37° C in the presence of 5% CO2 for 48 hours at which point they were examined microscopically to determine any change in cell morphology. Under the conditions of this study, the 1X MEM test extract showed no evidence of causing cell lysis or toxicity. The reagent control, negative control and the positive control performed as anticitpated. Therefore the requirements of the study were met.
