Bioreactor Sterilization: What You Need to Know

Bioreactors — vessels designed to promote the growth of organisms such as yeast, bacteria or animal cells under controlled conditions — are a critical component in biotechnology companies, and a common device used in both established firms and startups.  In order to prevent contamination, which can be incredibly costly in by time lost and money spent, it’s important to properly sterilize bioreactors between uses.

Although there are multiple different methods of sterilizing a bioreactor, steam sterilization is the most common — and the most effective. Here are a few things you should know about sterilizing a bioreactor using an autoclave.

Can My Bioreactor Fit in the Autoclave?

All too often, biotech facilities mistakenly assume that their existing autoclave is large enough to accommodate a bioreactor, or they purchase an autoclave without taking the dimensions of the bioreactor into consideration.  For example, bioreactors from particular manufacturers must be loaded into an autoclave in a specific orientation, or must be loaded on particular secondary containment structures.   In other words, you might not be able to simply load into the autoclave in the vertical position.

Also, depending on its size and weight, a bioreactor may be far easier to maneuver into the autoclave when placed on a wheeled loading cart and carriage rather than on stationary shelves within an autoclave. To avoid any complications, be sure to talk to an autoclave specialist about the dimensions of any bioreactors you may need to sterilize.

Which Sterilization Cycle Do I Use for my Bioreactor?

Typical bioreactors are large heat-resistant containers that do not usually have sensitive components, which means the primary concern for sterilization is ensuring that there are no air pockets trapped within the container itself. A pre-vacuum cycle is usually the best way to ensure that air can escape the bioreactor prior to sterilization taking place, as well as following any and all manufacturer guidelines with regards to positioning and partial or full disassembly of the bioreactor within the autoclave. Manufacturers of such specialized equipment will often have highly specific guidance when it comes to sterilization procedures, and this guidance should always be followed.

Certain bioreactors require specialized autoclave cycles. For example, Alternating Tangential Flow (ATF) bioreactors use hollow fiber filters that are easily damaged by rapid changes in either temperature or pressure. Therefore, ATF bioreactors require a sterilization cycle that gradually increases temperature and pressure, allowing these gradients to equalize across the filter. Properly sterilizing ATF bioreactors require a number of software and hardware customizations as well.

In order to avoid any potential damage, be sure to consult an autoclave specialist about which sterilization cycle to use for your specific type of bioreactor (or bioreactors, as the case may be).

Other Key Considerations

For organizations such as a biotechnology incubator space or a shared lab facility that house multiple different companies conducting different types of research, it may make sense to acquire an array of autoclaves to accommodate the various types and sizes of bioreactors that require sterilization.

If you have any additional questions about what type of autoclave or sterilization cycle to use for your bioreactor(s), talk to the experts at Consolidated Sterilizer Systems. We have experience supplying autoclaves for some of the leading biotech companies and incubators in the world