CO2 incubation experiment and some lessons learned!
I’m running the first set of CO2 carboy experiment samples today. There was a moment of shock this morning when I returned to the lab only to discover the fact that the LN (liquid nitrogen) had gotten frightfully low in my dewar that also contained samples yet to be run. Thankfully the combination of both a dry shipper liner within the LN dewar as well as the cryo-preservative glut that was used on the samples seems to have prevented any major loss. I ran a full set of the carboy experiment at all concentrations of carbon dioxide just to be sure.
The lesson learned: do not remove a complete set of samples and store in dewar until right before they are run. In case there is any leakage of liquid nitrogen from the dewar, removing them from -70 storage just prior to running the samples the same day will prevent complete thawing and loss.
What’s the other lesson here? don’t remove a duplicate set as well. The experiment took place in a duplicate set of carboys so in a sense, there was a duplicate experiment taking place each time. This resulted in a carboy A and carboy B set of samples. I should have only removed all of carboy A first and then run those prior to removing carboy B samples.
And, the final lesson. This is a surprising one since I am a very detail-oriented person. If I try to refer to my own notes in addition to a protocol that I wrote up just for running samples and things are still unclear, it’s time to revisit the note-taking effort in the lab notebook. It’s probably also time to revisit the protocol and make sure that it is detailed enough so that someone who wanted to re-run some of my cruise samples could pick up the protocol and go through it exactly the same way that I would have if I were running the samples.
This lesson is slightly more urgent since I have to confirm that I indeed stained and dilulted at the correct concentration for these carboy experiment samples prior to running any more later this week! Ah, the hard lessons of science – Part I.