8 thoughts on “P57 – Richins

    1. This model organism is both in the family of bacteria that are pathogenic and it is inert. Phage that can infect M. Smeg have a higher chance of being able to infect bacteria that are closely related to M. Smeg like M. Tuberculosis.

  1. Great presentation, don’t know why you were upset at the end! How did you calculate the High Titer Lysate?

    1. I thought I had forgotten to hot record and didn’t have time to crop it lol. We calculated the titer of the HTL by diluting the HTL until there were 20-200 plaques present on a plaque assay. We then used the level of dilution, and the volume of diluted lysate to calculate the number of plaque forming units in the original HTL.

  2. Is there a reason that you expected M. Smeg infecting phage would be present in the soil sample but didn’t mention any other potential phages that could be present? What does it mean to have to enrich the sample with M. Smeg and why is that a necessary step?

    1. There are likely many phage that infect many different kind of bacteria in the soil sample that we collected. We used M. Smeg because it was known that M. Smeg infecting phage would likely be present, and because M. Smeg is an inert (non disease causing) bacteria that is closely related to bacteria that are pathogenic like M. Tuberculosis. Enriching our soil sample means that we put our soil into a flask with M. Smeg in a solution conducive to the continued reproduction of M. Smeg, and incubated this soil + M. Smeg solution for 48 hours. This allowed for phage present in the soil sample to infect the M. Smeg and therefore amplify the concentration of phage in the sample.

  3. what other experiment (apart from what you listed) can help audience understand the sequence of your phage or usefulness of your phage?

    1. There are two experiements that would have been performed in the course of our lab that would have assisted us in characterizing our phage: restriction enzyme digest, and PCR. I discusses restriction enzyme digest in the video. The other, PCR, consists of amplifying our DNA using primers that are specific for specific clusters of phage. If the primers of a cluster are effective at amplifying the DNA it can be assumed that the phage belongs to that cluster. The clusters give us an idea of the genetic make up of the phage. This can give us a better idea of many qualities about the phage, such as whether the phage is lytic or temperate, the specific lysins in the genome, the and the subtype of phage structure, as well as many other properties. These are important to consider when considering a phage for inclusion in a phage cocktail for application in phage therapy.

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