For all my tough talk, I never did make my third year students write an SOP [standard operating procedure] for the autoclaves which we used every week in F&F - Food and Fermentation Microbiology. This was partly because my services were not required last year for that course because we could only muster 30 Yr3 students. We are back to 3 lab-groups again this year and the course starts today. But I'll be sure to implement my cunning plan of appointing a rotating Autoclave Liaison Officer each week who will, under my eagle eye, load and fire up the autoclaves; so that they have something to pour into their Petri dishes.
Earlier in the week I had my first session supervising wet-lab research projects. I have set my own nine [computer] project students going in their several directions along the edge of the frontiers of science. They have a longer, less intense schedule, so that both lots have a nominal 180 contact hours to make their mark on the world of understanding. If you want, you can treat supervising wet-lab research projects as a dosser's hour between more intense classes: some of my colleagues catch up on marking, some read the newspaper, some prep classes. The only requirement is that there is an adult in the room as the students trick about with potentially dangerous materials. If something goes wrong, we-the-adults should be there and should know what to do, who to call, if something goes wrong. I hadn't been in the job a wet month when one of my people sustained an acid burn. Two years later we had two hot-glop accidents involving students who had been trained <ahem>in the correct use of the autoclave.
My inherently nosy and curious nature would rather find out what the students were doing in their projects than read the newspaper and I hate marking lab books. I therefore made the rounds to find out the aspirations, or at least the game plan, for the three students who had rocked up to class on the first week of project work. In the previous hour two of them had made up some agar and set it all going in the autoclave to sterilize the stuff. Several things were amiss:
- One autoclave was all battened down and heating up but the lid was cold to the touch. That cannot be right because the interior of the pressure cooker has to be full of live steam not mere hot air. But that was okay: just open the steam valve and allow the boiling water to expel the air.
- The other autoclave was never going to come up to pressure because it was shrieking steam from between the lid and the base. I thought the rubber seal-ring might be kinky [it was the last time this happened] so we had to switch off the heat, wait for the pressure and temperature to drop and then check the seal and start again.
- That hypothesis turned out to wrong because the shrieking symptoms were repeated. Called technician. Technician asserts that there can be nothing wrong with her autoclave as it just came back from its biannual service. Then she noticed that the number on the lid (1) did not match the number on the can (2). Some noodle-head had swapped the lids which can be as idiosyncratic about fit as a rifle and its bolt.
- The third autoclave was too full of water. Bad because it takes longer to heat up; worse because everything floats about. We emptied a couple of litres out and set it going.