Hello V H Krishna Prasad

There are many methods to sterilize CO2 incubator. Three of the most common methods are:

1. UV sterilization

2. Moist heat sterilization

3. Dry heat sterilization

However, there are significant drawbacks if you use UV sterilization. The light source would need to have unrestricted access to all surfaces of the incubator chamber, shelves, and shelf mounting hardware. Shadowed regions will not be decontaminated by a UV light. Also, a common method for microorganisms to survive UV exposure is through enhanced DNA repair mechanisms. In this case, survivors of a UV cycle will be more likely to survive repeat treatments. Moreover, UV light is generally not effective in destroying endospores. Microorganisms which survive the UV decontamination process will potentially have the opportunity to form monocultures and increase their likelihood to reach quorum. This is unless UV sterilization is combined with other methods of incubator decontamination, such as a tear-down and washing of all surfaces, a dispersed chemical treatment, or an effective high-heat cycle.

The type of sterilization method best suited for your incubator will depend on the design and specifications of your machine.

Moist heat decontamination is often employed on incubators that are not designed to safely reach the high temperatures needed for an effective dry-heat sterilization regime. This may be due to a risk of damage to internal components or the risk of overheating the incubator’s outer body. A moist heat decontamination cycle performed close to 100°C and at ambient pressure is guaranteed to be less effective.

On the other hand, dry heat sterilization at 160-180°C for 4 hours will kill all known microorganisms. An incubator designed to handle dry-heat sterilization is akin to an oven with a self-cleaning cycle. Both are designed to handle much higher heat loads than typical operating conditions without experiencing damage or presenting hazards, and so are manufactured to be tougher and meet a higher standard of quality than non-high heat units.

High heat dry sterilization will kill bacteria in the chamber that may be located in shadowed crevices such as the undersides of shelves and within shelf mounting hardware, and can serve as a substitute for having to remove all your shelving to autoclave it.

If your incubator does not have the sterilization facility, you may fumigate with formaldehyde and potassium permanganate. Formaldehyde vapour is very useful for fumigating culture room as well as CO2 incubators. Fumigation of CO2 incubator is not generally advisable, but since the incubator has been kept non-functional for long, you may try this way out.

After the CO2 incubator becomes functional, you will have to maintain sterility. Once a month, empty the CO2 incubator fully. Using a lint free cloth, clean the chamber interior with soapy water and rinse with water, followed by wiping the surfaces with 70 %alcohol or an equivalent non-corrosive disinfectant.

Best.

Thank you very much for your reply dear Malcolm Nobre

@Malcolm Noble

If you cut and paste please identify the source - the above is cut and paste from https://labincubators.net/blogs/blog/methods-of-incubator-sterilization

Dear Dr. Phil Geis,

Okay! Will do it next time. I must have missed it out due to lack of time. Anyways, thank you for your suggestion.

Warm Regards,

Malcolm Nobre

Dear V H Krishna Prasad

Further to my above answer, you may want to refer to the link mentioned by Dr. Phil Geis for more information, which I missed to include in my answer. It was kind of Dr. Phil Geis to have brought this missing link to my notice.

Best Wishes,

Malcolm