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Instruction manual - G95
Kivex Biotec Ltd
9. Gassing of CO² incubators
9.1. Why gassing?
Most of the culture media which are used in assisted reproduction techniques are sensitive to changes
in pH. Culture media must be maintained at a pH about 7.4. This can be obtained by gassing with an
atmosphere of 5� or 6� CO₂.
9.2. Gas supply
Gas mixtures are typically supplied in 50 liter steel tanks with a pressure of 150 bar (2000 PSI), however
smaller tanks are also available.
9.3. Gas pressure
The gas pressure must be reduced by using a two stage regulator.
It is recommended that the range of the output pressure on the two stage regulator is 0-2 bar (0-27 PSI).
The output pressure from the two stage regulator must be set between 0.5 and 1.0 bar (4-10 PSI).
9.4. Humidifying the gas mixture
In order to reduce evaporation from the culture media, humidification of the gas mixture may be
necessary if larger gas flow rates are used.
We recommend the K-SYSTEMS GH01, which must be connected between the regulator and the G95
portable incubator.
9.5. Gas flow rate
In general, the flow rate should be between 5 - 20 litres per hour, depending on the application and how
often the lid of the portable incubator is opened.
The flow rate should not be higher than necessary in order to reduce the risks of changing the
osmolarity of the culturemedia.
To quickly establish the correct CO₂ concentration, it is recommended to gas with 6 litres of 5� CO₂ in air
for instance, with the K-SYSTEMS GH01 flowmeter set at 29 l/h gas for approx. 15 minutes.
Higher flow rates can be used if the flow meter has a flush-flow valve for rapid purging.
