Monday, 12 July 2010

Always Check Your Notes

Today I made a relatively inconsequential but annoying error.
I'd also made one last Friday as well.
In chronological order, last Friday when I cleaned out the flasks I didn't rinse them out sufficiently, meaning there was some residual Virkon (raspberry sherberty bleach stuff) in all 5. This stopped the bacteria from growing quite as well as they usually would (which is fortunate in one way; bleach that allowed or potentiated bacterial growth would be both useless and still not delicious). That was a bit of a bummer, and I read their optical density (OD) at 895nm to check that they weren't as numerous as I'd hoped. Dr J posited that we leave all but one of the flasks in the cold room, and if there were none in the solitary flask the next day we could re-inoculate. I left them for another three hours before reading their OD again; this time they definitely smelt of bacteria, and they were pretty cloudy and warm, but the OD was still pretty low. Subsequent investigation revealed I should have been reading the absorbance at 595nm, which makes a lot more sense. Turns out we have more than enough cells, so I inducted and slammed them back into the incubator overnight. It's a pretty simple mistake and I'm annoyed that it stopped me from doing more with today, but it's not one I'm going to repeat.

Lookit my flasks! Clearly full of microscopic protein factories.

As a brief digression, I think it's time I talked about gloves.
The gloves I've been using are totally kick-ass. They're dry nitrile gloves (like the ones in the chemistry laboratories) rather than the awful loose powdery ones the 1st and 2nd year bioscience students get; but unlike the chemistry gloves these ones are purple. Purple, asides black and possibly neon green, is the best colour for gloves. Unfortunately, they are *dry* nitrile gloves, so if hands are wet (say from something as innocuous as a recent handwash), they're almost impossible to don. Here is a visual illustration of today's struggle:

Getting the glove onto the hand can be tricky, but once on it's usually just a matter of working through finger by finger.

Success! This took about a minute and a half. Now for the other hand!



  1. omg.. the purple gloves.. i remember nicking a pair on the b'ham open day.... i think i also broke a glass slide from playing with the microscope too much on that particular outing too....

  2. You're a terrible scientist.