Gas Mixers Okolab, Tokai & Biostation November 24, 2009

If you are planning to use a microscope stage top incubator system for extended periods of time you probably will need some type of external gas combination, usually CO2 and air, to keep the cells alive. As you work with different systems you will find the individual requirements can vary significantly and if you are not careful, you can damage the system.

Two of the most common mistakes are not using the correct air pressure from either the gas tank or wall into the gas mixers and the wrong flow rate from the mixer to the specimen chamber. Based on the diagrams you will see that the input pressure to the different mixers, NOT the specimen chamber, varies between 7.5 to 30 PSI (pounds per square inch). The flow rates to the specimen chamber vary between 0.l to 1.0 L/min (liters per minute), again depending on the model and manufacturer of the mixer and chamber.

When working with gas tanks it is important to note that there are two types of regulators typically used; single stage and two stage. They both look similar with tank and output pressure gauges but the two stage regulator has two internal pressure reduction stages that maintain a constant output pressure even as the tank pressure decreases. They are recommended when small changes in pressure are not acceptable. There are different ranges for the output gauge, but typically 0-30 PSI is recommended.

Following are diagrams and some general recommendations to consider when working with the Okolab, Tokai and Biostation systems including supply and input pressures, regulators, as well as filter requirements. This information is considered only as supplemental and does not replace the individual instruction manuals. Always make sure you refer to the individual instruction manuals for both the controller and incubator prior to connecting any gasses.

Okolab Okolab manual and digital gas mixers have similar input and out put ranges and can be used with all of the Okolab stage top incubators and other similar devices such as the Biostation IM. If your supply tank does not have a verified “two stage” regulator you may want to consider a GFR regulator or equivalent in the supply line to the mixer. If you will be using wall supplies for either air or specialty gas requirements make sure it is filtered and has an adjustable pressure gauge. If not you may want to consider adding a GFR regulator or equivalent in the supply line to the mixer. The part number for the GFR Regulator is 77057223. Okolab has an alternate air supply source to eliminate the need for either air tanks or air supplies from the wall. The 77057224 Air Pump provides a constant regulated 15 PSI output and has an internal air filter and works with both the digital and manual mixers. Filtration is extremely important because it removes dust, moisture and bacteria from the lines which can affect the performance and accuracy of the gas sensors and also contaminate the sample chamber. Carefully follow the instructions in the manual when connecting the different tubes and filters together because some filters have direction and some hoses may have different diameters and specialized fittings. When connecting the different tubes keep in mind they may have different diameters and connectors depending on their location and use. Simply connecting the tubes together without checking the instructions can affect the flow rates between the devices if the diameters are incorrect.

Tokai

The Tokai system is an all-in-one system that includes control of the electrical components of the stage incubator, a built-in air pump and gas mixer. If your supply tank does not have a verified “two stage” regulator you may want to consider a GFR regulator or equivalent in the supply line to the mixer. If you will be using a wall supply for the CO2 make sure it is filtered and has an adjustable pressure gauge. If not you may want to consider adding a GFR regulator or equivalent in the supply line to the mixer. Filtration is extremely important because it removes dust, moisture and bacteria from the lines which can affect the performance and accuracy of the gas sensors and also contaminate the sample chamber. Carefully follow the instructions in the manual when connecting the different tubes and filters together because some filters have direction and some hoses may have different diameters and specialized fittings. When connecting the different tubes keep in mind they may have different diameters and connectors depending on their location and use. Simply connecting the tubes together without checking the instructions can affect the flow rates between the devices if the diameters are incorrect.

MXK37282 MIGM Digital CO2 Mixer for Biostation

The MIGM CO2 mixer has a built-in air pump and gas mixer. DO NOT connect the “Air In” connector on the back to an external air supply. It is there so an external air filter can be connected. If your supply tank does not have a verified “two stage” regulator you may want to consider a GFR regulator or equivalent in the supply line to the mixer. If you will be using a wall supply for the CO2 make sure it is filtered and has an adjustable pressure gauge. If not you may want to consider adding a GFR regulator or equivalent in the supply line to the mixer. Filtration is extremely important because it removes dust, moisture and bacteria from the lines which can affect the performance and accuracy of the gas sensors and also contaminate the sample chamber. Carefully follow the instructions in the manual when connecting the different tubes and filters together because some filters have direction and some hoses may have different diameters and specialized fittings. When connecting the different tubes keep in mind they may have different diameters and connectors depending on their location and use. Simply connecting the tubes together without checking the instructions can affect the flow rates between the devices if the diameters are incorrect.

Conversion Factors http://www.asknumbers.com/

PSI x 0.0068947 = Megapascal Megapascal x 145.0377377 = PSI PSI x 0.068947 = Bar Bar x 14.50377377 = PSI Liter/minute x 1000 = Milliliter/minute Milliliter/minute x 0.001 = Liter/minute

Okolab Two Gas Manual and Digital Gas Mixers

PSI = 30 Megapascal = 0.207

Alternate to CO2 tank Use Compressed CO2 line from wall

CO2 or N2

2GF-MIXER DGT-CO2BX DGT-O2BX

PSI = 15 Megapascal = 0.103

PSI = 15 Megapascal = 0.103

PSI = 30 Megapascal = 0.207

Alternate to Compressed air line from wall Pump with 15 PSI output #77057224

GFR Regulator w/filter

(Max 90 PSI Input)

Consult Manual for Float valve settings

Okolab Three Gas Manual Gas Mixer

PSI = 30 Megapascal = 0.207

PSI = 30 Megapascal = 0.207

PSI = 15 Megapascal = 0.103

3GF-MIXER Consult Manual for Float valve settings

PSI = 30 Megapascal = 0.207

PSI = 15 Megapascal = 0.103

Alternate to CO2 tank Use Compressed CO2 line from wall

GFR Regulator w/ filter

(Max 90 PSI Input)

Alternate to Compressed air line from wall

Pump with 15 PSI output #77057224

CO2 or N2

PSI = 15 Megapascal = 0.103

Tokai INUG2A, INUG2E TIZ

PSI = 15 (to 30) Megapascal = 0.103 (to 0.207)

Alternate to CO2 tank Use Compressed CO2 line from wall

GFR Regulator w/filter

(Max 90 PSI Input)

MXK37282 Digital C02 Mixer for Biostation

PSI = 7.25 Megapascal = 0.05

Alternate to CO2 tank Use Compressed CO2 line from wall

Has internal air pump

GFR Regulator w/filter

(Max 90 PSI Input)

To Biostation Humidifier Set flow to about 150 - 200 ml/min Good bubble flow through humidifier water but not violent