Biological incubators/bioreactors are a vital piece of equipment required for the growth of many cell types. Incubators are ubiquitous in any cell biology or DIYBio lab and at their heart they are simply warm, humid boxes with temperature and atmosphere regulation. Incubators for bacterial culture are cheap and easy to come by because they are essentially warm, humid boxes. Many DIY designs exist and are routinely employed by DIYBio and academic labs. These incubators are great for anyone wanting to grow, genetically modify and manipulate bacteria. However, if one wants to grow mammalian cells (eg. human cells, mouse cells, etc), incubators are required that control both temperature and the CO2 content of the atmosphere. Maintaining an atmospheric CO2 concentration of 5% is essential for maintaining the pH of common mammalian cell culture media (ex. DMEM) . There are some CO2-independent media formulations on the market but they can be expensive, the cells never seem to grow very well and they often look “a little funny”.
So what is a cheap/poorly funded academic and/or DIYBio person to do? Commercial incubators routinely cost between ~$5,000 (and up!) and remain fairly expensive even on the used market. The high cost of these incubators is not only prohibitive for the DIYBio community, but also for academic labs. In our current funding landscape, countries are continually slashing their science funding budgets yet these these incubators remain a vital resource to researchers in the biomedical sciences. Moreover, scientists in emerging/developing nations may not have access to levels of funding that would permit them to purchase, and maintain, CO2 incubators.
My lab is often asked if we have developed plans for a DIY CO2 incubator because of these issues. After spending some time looking around at what is available on the web already, I found myself unsatisfied with existing forum discussions and projects. So I’ve decided to give it a shot myself.
There are really three main challenges that need to be solved in order to implement a DIY CO2 Incubator:
Obtaining the right CO2 sensor.
Controlling the CO2 content of the incubator atmosphere at 5%.
Finding a CO2 source that is easy to acquire.
Over the past few months I have developed a working DIY CO2 incubator while on sabbatical at SymbioticA, University of Western Australia. I gave myself the challenge of building it for under $500 and using as many recycled/found materials as possible. The design presented here addresses the three challenges above and I built mine for ~$350 (by far the most expensive part was the actual CO2 sensor at ~$230). Hopefully the information on this site is of use to the DIYBio and global academic communities.
The completed DIY CO2 Incubator for Mammalian Cell Culture Incubator
Maintains 37.0 ± 0.1 Celsius and 5.0 ± 0.2% CO2
Disclaimer: The plans and code provided here represent the first shot at a workable solution. They are seriously “Quick and Dirty”. They are not perfect but the incubator functions well and will support the culture of mammalian cells. You are encouraged to use the information on this site as a starting point for your own projects. Please share any changes you have made to improve the implementation of this incubator and contact us if you have questions.
These instructions are presented in 5 different sections:
>>> [NEXT] Design and Build
>>> Arduino and Circuits
>>> Proof is in the Pudding
>>> Possible Improvements
This work was made possible through financial and in-kind support from the Raine Medical Research Foundation, SymbioticA, The School of Anatomy, Physiology and Human Biology (UWA), The Natural Sciences and Engineering Research Council and The University of Ottawa.
DIY CO2 Incubator for Mammalian Cell Culture by The Pelling Lab is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.