Link to this post | posted 24 Mar, 2025 15:01

anne8

Is it possible to get fresh A. globiformis from UPitt? Would I need to go through all the legal hoops again to do so? Our lab techs believe that when we received our original stock last summer that it was stuck in the freezer immediately and that is causing our problems. I am thinking of asking MCC if they will give us some host. We have been seeing plaques on plates only to lose them when we try to purify/amplify from webbed plates. Checking the forums I saw that we have probably been working with a contaminant since Phage Liebe will not infect the bacterial lawn. Streaking out our stock yielded no growth. Streaking out what we though was Arthrobacter yields two different morphologies. One is clearly a contaminant and the other I hope is Arthrobacter, but won't know until later this week.

Link to this post | posted 24 Mar, 2025 15:21
debbie	Hi Ann, Yes, we can resend and depending on the dates of the MTA, no further paperwork is required. Would you send me an email for this (djs@pitt.edu). Please include your shipping address (and phone number), or confirm that information is on seaphages.org. Best, debbie

Link to this post | posted yesterday, 19:35

anne8

We have plaques now. However, one group's plaques have a "bullseye" appearance to them. (See attached.) This result is after 48 hours of incubation. None of the other student groups' plaques have this appearance. My first question is should this group discard their plates and adopt someone else's phage? I went searching online and one suggestion was that the bacterial lawn was old. However, all students in this lab section received the same Arthrobacter globiformis host so shouldn't all the student groups have seen this phenomenon? 698Kb

Link to this post | posted yesterday, 19:36

anne8

We have plaques now. However, one group's plaques have a "bullseye" appearance to them. (See attached.) This result is after 48 hours of incubation. None of the other student groups' plaques have this appearance. My first question is should this group discard their plates and adopt someone else's phage? I went searching online and one suggestion was that the bacterial lawn was old. However, all students in this lab section received the same Arthrobacter globiformis host so shouldn't all the student groups have seen this phenomenon? 698Kb

Link to this post | posted yesterday, 20:24

debbie

Hi Anne, Did you plate the control phage, Liebe, originally sent to you? If that infects and looks as expected, you should be fine. I believe we re-sent bacteria and the thought was that the bacteria you had was contaminated. Different phages can make different plaques, so that is OK. I am not sure what you are asking. So if you have more questions, let me know. With the bacteria we sent, you should re-hydrate and grow up a streak plate. Your cultures should always be made from a single colony. Do not continually repropagate from a liquid culture. I would also recommend as you grow up a culture to streak it out to make sure there is only one colony morphology and that it looks like what is expected. anything else? debbie

Link to this post | posted yesterday, 20:43

anne8

Hi Debbie, Yes, Liebe infects great. We are also culturing from an Arthrobacter streak plate with one colony picked each time. I needed reassurance that plaques can look like bullseyes. Since this is the case, we have been able to isolate 3 different morphologies: large & clear; small & clear, bullseye. We will do a 2nd round of purification this week using Arthrobacter cultured from a single colony from a streak plate made from the new stock we received. Thank you for the quick response. Anne