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All posts created by cellokiwi

| posted 13 Jan, 2020 21:01
Hello Hive Mind

I'm hoping I can get some help with a one step growth curve. My students have tried two different protocols, one of which works successfully in another mycobacteriophage lab, and we have not been able to get a nice S-curve. There is a trend that we see every time, high titer initially that continues to drop. The earliest time point we have tried (other than 0 min which has no plaques) is 10 min and I honestly refuse to believe that they are completing a replication cycle that quickly… So why do we have essentially inverse data to what you would expect? Again, this is highly repeatable; we have tried many times. I'm attaching a representative graph of what we are seeing. Thanks for any and all help we can get!
Posted in: Phage BiologyOne Step Growth Curve
| posted 15 Oct, 2019 15:00
We finally had success again by doing 2 things. We let the culture get older in the shaking flask before plating and we doubled the amount of bacteria (from 250 uL to 500uL) when we plated. I still don't know what to do about the fridge plates degrading. Letting them sit at room temp just makes this microbiologist get a nervous tick… lol. Good luck!
We are having the exact same problem right now as you describe cellokiwi with A. globiformis.
After incredible success in the first few several weeks with several of our students reaching high titer and others just needing to titer their likely high titer lysates, we have been met with a standstill for the last week and half unable to get an adequate lawn plate from our bacterial liquid culture(s).
Most of our attempts at lawn plates have either given us NO lawn at all (after 24 hrs, our typical incubation at 30 degrees) or a very inconsistent/spotty lawn.
We have restreaked from several glycerol stocks onto new PyCa plates and remade our liquid PyCa media and top agar.
Any other thoughts would help as well for us in order to get our last students through the last steps and to the DNA extraction phase.
Thank you,
Posted in: ArthrobacterSuccess followed by failure?
| posted 11 Oct, 2019 15:36
Streak Plate
Posted in: ArthrobacterSuccess followed by failure?
| posted 11 Oct, 2019 15:35
Hi Vic,

Sorry for the delay. Attached is a picture that has the plate the day we first looked at it next to how it appeared after maybe 2 weeks in the fridge. It is so weird. It will only let me add one attachment to the post so I will put a second with a picture of the streak plate.
Posted in: ArthrobacterSuccess followed by failure?
| posted 09 Oct, 2019 01:44
I will snap a picture of the streak plate in the am and post it.
Posted in: ArthrobacterSuccess followed by failure?
| posted 09 Oct, 2019 00:56
Hello Hive Mind,
We are having a rather weird problem that has persisted for a few weeks. We started the semester with Arthrobacter growing well. It formed beautiful lawns, we had the majority of students with plaques, some progressing as far as flooding a webbed plate. They just needed to start titering. Then things suddenly stopped working. We can't get a nice lawn anymore to save our lives. We have tried refreshing the LB plates, the top agar, the CaCl2, all of it. We went back to the first streak plate (that worked initially), didn't work. Went back to the sample sent from Pitt, didn't work. I'm running out of ideas as to why something that worked beautifully before is suddenly crashing and burning. Weird thing #2: Some students that put their plates with plaques in the refrigerator (wrapped in parafilm) went back to check them and the lawn was disintegrated to the point that you could no longer see the plaques. What is UP with this organism? Any and all tips/help is GREATLY appreciated!
Posted in: ArthrobacterSuccess followed by failure?
| posted 22 Aug, 2019 21:00
Students can't find the app in the Apple AppStore or the Google Playstore. Did it get taken down?
Posted in: SEA-PHAGES AppIs it gone?
| posted 19 Jun, 2019 17:53
Thank you so much! Miriam is listed as the primary contact so I've given her a heads up that you guys will probably be emailing her. Everything else on the institution page is correct and good to go.
Posted in: ArthrobacterA. globiformis aquisition
| posted 17 Jun, 2019 18:03
I would like to start using A. globiformis as the host for phage hunting this fall semester. Since this organism is not in ATCC, as far as I can tell, how do I get a starter culture? Thanks!
Posted in: ArthrobacterA. globiformis aquisition
| posted 14 Jan, 2019 16:42
We are trying to calculate burst size for our phage but are having trouble getting a one step growth curve to work reliably. Is there a popular protocol that people use with smeg that works well? Thanks!
Posted in: MycobacteriumOne Step Growth Curve