CO₂ incubator
A warm, humid chamber that holds mammalian cell cultures at body temperature (usually 37 °C), high humidity and a set CO₂ level (usually 5%), so the culture medium stays at the right pH.
- Biotechnology
- Biopharmaceutical
- Cell and gene therapy
- IVF clinics
- Academic research
- Vaccine manufacture
How CO₂ incubator works
The chamber is heated to the set temperature and a CO₂ sensor measures the gas concentration. When CO₂ falls below set point, a solenoid valve injects CO₂ until the set level is restored. In the medium, dissolved CO₂ forms carbonic acid, which balances the sodium bicarbonate in the medium to keep a stable pH. A water pan keeps relative humidity at typically 90–95% to limit evaporation from cultures.
The path of a sample
- 01
Heat
Heaters in the walls (direct heat) or a water jacket bring the chamber to set temperature.
- 02
Measure CO₂
The IR or TC sensor continuously measures CO₂ in the chamber air.
- 03
Inject CO₂
A valve admits CO₂ through a filter when the reading is below set point.
- 04
Humidify
Water in the pan evaporates and keeps humidity high.
- 05
Circulate
A fan or natural convection keeps temperature and gas even across shelves.
- 06
Monitor and alarm
The controller logs values and raises alarms if they go out of range.
Main parts and what they do
Chamber and shelves
Stainless steel or copper-alloy interior with removable shelves for cleaning.
Heating system
Water jacket or direct heat (air jacket) with a controller.
CO₂ sensor
IR or TC sensor that measures CO₂ concentration.
Gas inlet and filter
Solenoid valve and in-line HEPA or 0.2 µm filter for CO₂ supply.
Humidity pan
Holds sterile purified water to keep humidity high.
Inner glass door
Lets you look in without disturbing the atmosphere much.
Controller and alarms
Displays set and actual values, logs data and gives audible/remote alarms.
Terms every analyst should know
Bicarbonate buffer
Sodium bicarbonate in the medium and CO₂ in the air form a buffer. The right CO₂ % depends on the bicarbonate level; 5% suits many common media.
IR sensor
Measures CO₂ by its absorbance of infrared light. Accurate and largely unaffected by humidity or temperature.
TC sensor
Measures the change in thermal conductivity of the air caused by CO₂. Cheaper but sensitive to temperature and humidity.
Recovery time
The time for temperature and CO₂ to return to set point after a door opening. Typical specifications are a few minutes for CO₂.
Temperature uniformity
The difference between the warmest and coldest points in the empty chamber, measured with several probes during mapping.
Keep every CO₂ incubator in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.