What a Flask Looks Like When Yeast Has Outgrown Everything
The domeless cell culture primary cells I set up last week have been taken over by either may fly cells, yeast cells, or some other contamination. We have pretty much decided it is yeast cells. Any alive yeast not killed by the autoclave will propagate in the flasks. The yeast used for the domeless was used for the myd88 flies the week before with no issue, but it had sat on the bench for the week (covered), potentially a live yeast got in. Or the tool used for making the plates had live yeast on it and then spread it to the domeless plates. I think it is unlikely to be some other contamination because all 4 flasks had the same growth, but were done on different days. Plating the yeast was the same day. Also I felt like I was being very cautious about sterile technique when preparing the flasks, wearing gloves etc. And the innubila flasks (some of which were made the same day) do not show signs of growth like these.
Unfortunately we have a new yeast brand now, and so I don’t have a picture of the yeast that was used to make the domeless plates. This is a 20X picture of the new yeast on a microscope slide:
And these are the domeless flasks after less than a week of being in culture at 20X
This is what the flasks looked like the day they were set up:
