placed freshly thawed cells in culture bottles, and the medium (which before entering into contact with the cells was of a pH of 7.4) becomes fuchsia (alkaline). Is it due to poor regulation of the co2 incubator?
If your media is going purple in the incubator then something is wrong with the CO2 setting of the incubator or the media formulation--either way they are incompatible. Either your media is tuned for say 10% CO2--fairly rare, but not unheard of--and your incubator is 5% CO2 or you are not actually getting 5% CO2--not uncommon. Ensure you have a proper and functioning regulator for your CO2 tank, this was a failing point for our lab--cheap improper regulator which started to fail.
thats unlikely unless its known unstable incubator, did get rid of the cell banker or whatever solution used to store the cells? that is a toxic and alkaline if u didnt wash it away before u add regular media this will kill ur cells.