Talk:Setting the oxygen concentration

Template:Technical service Question: Can we set the oxygen concentration in the Oroboros-2k to desired levels?

Answer: Yes.

It is always possible to increase the oxygen concentration using the combination of catalase in the medium and injections of H2O2, as described in MiPNet14.3. By using the TIP2k the oxygen concentration can be maintained between well defined limits, either using H2O2 or (for very low oxygen concentrations) air saturated medium in the TIP syringes. We call this an "oxystat" approach and supply appropriate templates for controlling the TIP2k. See also MiPNet12.10.

This leaves the question of how low oxygen levels can be reached in the first place: In a biological experiment this may be done by inserting a N2 bubble into the chamber, waiting until the desired level of oxygen is reached and then destroying the air bubble by closing the stoppers. However, most often the desired starting value is simply reached by waiting until the sample has consumed the required amount of oxygen and then starting the "oxystat". For calibration and instrumental oxygen background purposes we use Dithionite to reduce oxygen levels, however this is not recommended in the presence of biological samples.