I know we've been through this before, but anyway.... I can't tell if I'm letting CO2 into the chamber too fast or too slow. If I turn the regulator down really low, it takes the mice over a minute to become unconscious. Is this too slow? If I turn the regulator up higher, they pass out faster. Either way they seem to start breathing heavy (hypoxemia) before they pass out.
So I just have to ask, for those of you who are good at this.... when you do it right, how long does it take the mice to become unconscious? Should I be turning the regulator up even higher so they pass out before they go into hypoxemia? But I know if you do it too fast that's not good either, they start flipping, etc...
I hate doing this, but I have too many mice and have no choice in the matter. I want them to suffer as little as possible. What am I doing wrong? I know the CO2 is supposed to displace at least 20% of the oxygen per minute, but I have no way to measure that.
