The official website of the HHMI Science Education Alliance-Phage Hunters Advancing Genomics and Evolutionary Science program.

Welcome to the forums at Please feel free to ask any questions related to the SEA-PHAGES program. Any logged-in user may post new topics and reply to existing topics. If you'd like to see a new forum created, please contact us using our form or email us at

Success followed by failure?

| posted 30 Oct, 2019 13:18
I am having the same problems. The culture produces plaques on Monday but not when they use they same culture on Wednesday. The plates in the fridge are also growing over the plaques. We are stuck on the amplification stage since we cannot get repeatable results to check for consistent plaque morphology. We tried letting the culture grow longer and that seemed to help one group of students get plaques again but the others did not.
| posted 30 Oct, 2019 13:28
Sorry for the delay. Things started working again, with no explainable reason. But now they are not again!
Perhaps its glassware issues? We always start with a single colony. We often just use an overnight culture of A. globiformis for our lawn plates and it was working just fine. We've recently switched to longer incubations, but have not seen a difference in lawn formation. We've been able to store the liquid culture for days/up to a week at room temperature and still use it for a lawn. But now this has not been consistent.
Luckily we have good DNA preps from all but two students, and we were just going back to try to make a fresh webbed plate to get fresh lysates for doing microscopy next week.
How fresh should these lysates be for microscopy? If we can't get fresh ones at the end of this week, some of ours are 1 month old.
Login to post a reply.