We finally got some good news this time!

Even though I did not get any plaques or lysing on my plate, there were about ten people from our class who did. I have to admit, it was disappointing seeing next to nothing on my Arthrobacter plate and rampant contamination on my smeg plate, but I am glad to know that there is some hope out there. We finally have results that suggest that finding phage that infect Arthrobacter is achievable, and that makes me even more determined to find putative phage in my own samples.

Today I did a little troubleshooting myself today and I think I have a hypothesis as to what happened with my Arthrobacter plate. I will post the picture of my plate, but it basically was a lawn except for the 10^0 section of my plate. That section had  a little bit of bacteria growing on top of the top agar, in a splattered pattern. I realized, after looking at my lab notebook from the previous lab, that while spotting my 10^0 serial dilution, I splattered the dilution, possibly from pushing down on the pipettor too quickly or releasing the liquid too far from the plate, onto the plate. The latter makes more sense, because no other section of my plate had contamination. I think that the 10^0 filtrate was exposed to bacteria in the air as I was transferring it to the plate, and subsequently caused bacteria to grow on top of the top agar. If this did happen, it makes sense that there was no other contamination on the plate, as the contamination occurred after I performed the serial dilutions.

Today I re-filtered my soil samples, and put them on a new plate. I tried really hard to minimize contamination by working quickly and keeping things covered when not in use. Hopefully, there will be no contamination and the re-filtering of the samples will result in some phage in my plate! Let’s keep our fingers crossed for Attempt #4!