The colonoscope is a semi-critical device because it contacts the mucous membrane of the colon. Therefore, it must be thoroughly cleaned and disinfected using a high level disinfectant. However, full liquid immersion or high temperatures can harm the device and the fragile camera lens. Given these constraints, it was determined that manual cleaning and disinfection using CIDEX would be appropriate. CIDEX is no longer commonly used, but at the time of this validation it was one of the most commonly used methods for endoscope cleaning. CIDEX provides high-level disinfection without corroding delicate device parts.

The device was first cleaned with water by partially immersing the device and using a soft sponge and water to clean the non-immersible parts. Next, the device was partially immersed in CIDEX OPA to enhance the cleaning. To disinfect the colonoscope, CIDEX Activated Dialdehyde Solution was used. The colonoscope was again partially immersed and was soaked for 12 minutes. A sponge was used to thoroughly apply CIDEX to the nonimmersible areas of the device. This combination of soaking and sponge application of disinfectant achieved the required microbial reduction while protecting the delicate instrumentation of the colonoscope.


A great deal of thought goes into the design of any medical device, and engineers should be encouraged to thoroughly examine the ways in which the design of their device can facilitate or hinder reprocessing. The best device design facilitates the use of the device, and also facilitates the reuse of the device. However, some devices, in the initial design, prove so difficult to reprocess that the design must be altered to facilitate cleaning and reuse. By understanding the choices made in creating a reprocessing methodology and how device design and use puts constraints on the reprocessing method, engineers can save significant amounts of time and speed device approval, thereby ensuring that their devices get to market as quickly as possible.

This article was written by Maria Lilibeth Samillano, M.D., Microbiologist and Device Team Leader; Diana Louie, Microbiologist; and Aaron Burke, Director of Business Development for Pacific BioLabs, Hercules, CA. For more information, Click Here .