What is a CO2-resistant shaker?

This article was published first in "Inside Cell Culture" , the monthly newsletter for cell culture professionals. Find more interesting articles about CO₂ incubators on our page "FAQs and material on CO₂ incubators" .

A CO₂-resistant shaker is used to agitate a small number of shake flasks with mammalian cells in suspension culture inside a CO₂ incubator. These cultures are, for example used for the expression of recombinant proteins or the production of bioreactor starter-cultures (inoculum). For higher throughput, CO₂ incubators with an integrated shaker are used.

The term “CO₂-resistant shaker” itself that is often used, also by manufacturers, is clearly misleading as it doesn´t address the main challenge these devices are facing and overcoming inside a CO₂ incubator. The elevated CO₂-concentration itself inside the incubator chamber is not the main challenge. However, together with the high relative humidity (usually ~95%) CO₂-resistant shakers face a slightly acidic atmosphere that is highly corrosive. In addition, this humid atmosphere can lead to electronic malfunctions and spills of culture medium entering the device may form a contamination nucleus that is hard to detect and remove. Therefore, in contrast to standard open-air shakers, a CO₂ resistant shaker comes with design specialized for the use inside a CO₂ incubator.

Features and limitations of a typical CO₂ resistant shaker:

• Low heat dissipation to avoid interference with the temperature control of the CO₂ incubator
• Sealed electronics and mechanical parts to avoid malfunctions, corrosion, and contamination inside
• Corrosion-resistant exterior made of stainless steel or specialized plastics like Acrylonitrile butadiene styrene (ABS) that can also be disinfected
• Platform capacity and drive design limited to shake a few 1L flasks (low throughput applications)
• Some devices are limited to 200 rpm and may therefore not be suitable for protocols with higher rpm of plates and tubes
• Limited use with parallel cultivation of vibration-sensitive adherent cells like stem cells or primary cells due to transfer of vibrations

Read more about the proper selection of a CO₂ resistant orbital shaker in our White Paper .

• Monthly Inside Cell Culture Newletter
• CO₂ incubator FAQs and materials
• White Paper “CO2 Resistant Orbital Shaker Selection and Comparison with Integrated Devices”