8 thoughts on “P36 – Topping

  1. You didn’t go over your methods section and it is not included in the poster, could you go into further depth on what the methods you used were?

    1. Yes definitely! The template our instructors provided did not include a specific methods section but I mentioned that we plated our bacterial samples on agar which is a common bacterial growth medium. This allows a lawn of the bacteria we chose (M. Smeg) to grow so we can see if the phage will kill that specific bacteria. We saw that the phage we collected did kill the bacteria because the plates showed small “bubbles” of space with no bacteria which we call plaques. However, because there were two different sizes of plaques we chose to continue the experiment by performing some dilutions of the initial sample to isolate the two separate phage. The idea behind these dilutions is to purify the sample.

  2. Hey Emma! I really enjoyed your background section I thought it was very informative. I see you hinted at a serial dilution and was wondering if that was the method and approach you took to getting your results?

    1. The serial dilutions are actually only a part of the full experiment! They are used to isolate individual plaques and purify the sample for better use in the larger experiment. In this case, we used the dilutions to separate the two kinds of phage that were present in our sample so we had a pure sample for electron microscopy.
      The overall method we chose to use was to plate the phage on a lawn of M. smeg grown on agar. This allowed us to observe the growth patterns of the phage which helped us to characterize it.

    1. I think you are asking about the different between lytic and temperate phage! Lytic phage are different from temperate phage in that they begin to replicate within the host bacteria immediately. Temperate phage can enter a different pathway in which they remain dormant for a time before beginning to replicate.

      The way temperate phage do this is by producing a protein which bind to the beginning of the gene sequence that causes the bacteria to replicate their genome. This prevents replication of the genome until that repressor protein is deactivated due to changes in the environment.

      Because temperate phages can stay dormant for long amounts of time, they are not as useful for treating antibiotic resistant infections.

  3. Do you think choosing a different location for soli collection in Boulder could vary the results?

    1. Definitely! We actually tested several soil samples from different places before this one. However, none of those samples contained phage that could infect M. Smeg and so they weren’t very useful for our experiment. There are millions of different phage with different host ranges and characteristics so picking a different kind of phage can give different results!

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