Surgical instruments, including hinged instruments, were inoculated with test microorganisms (ie, methicillin-resistantStaphylococcus aureus,approximately 2 × 106colony-forming units [cfu];Pseudomonas aeruginosa,approximately 3 x 106cfu;Escherichia coli,approximately 2 × 105cfu; vancomycin-resistant enterococci, 1 × 105cfu;Geobacillus stearothermophilusspores, 2 × 105cfu or more; orBacillus atrophaeusspores, 9 × 104cfu or more), coated with an oil-based lubricant (hydraulic fluid), subjected to a sterilization process, and then samples from the instruments were cultured. We found that the oil-based lubricant did not alter the effectiveness of the sterilization process because high numbers of clinically relevant bacteria and standard test spores (which are relatively resistant to the sterilization process) were inactivated.