The temperature and pH of the medium are critical to IVF success, however you do not have to be able to directly measure the pH to be confident of the pH level.
The pH of the medium is determined by the relationship between bicarbonate concentration, atmospheric CO2 concentration, and altitude. As long as altitude and exact gas concentration within the incubator are both known, the pH can also be calculated.
For IVF Bioscience media, this means that working with 6% CO2 will give the optimal medium pH at sea level. And at 1600m above sea level this would need to be upped to 7.1% CO2 to account for the lower atmospheric pressure. The same modifications would need to be made for the O2 concentration in the culture step. Anything below 5% is detrimental to embryo culture, so it is critical that these concentrations are accurately known and the altitude adjustments are made.
So, to be certain of your pH, measure the gas concentrations and temperature within the incubator, rather than trust the display.
A full chart of altitude adjustments is included in our protocols – get in touch to request further details.