Hi
In addition to the Mycoplasma poll. I am adding few other possible contamination in cell culture.
I would be interested to hear from you about the above contaminators.
Which one was the last that you had.

Guy

So what are we supposed to poll on?
Which infection we like best/prefer to have in our cultures?Which we fear most? Which of those we guess you had last month?

Thanks for the mail.
I wanted just to know which contamination is the most common in our cell cultures.
After that I will submit another poll.
GUY

This system dosent let you to put multiple question in one poll.
Guy

Can we add SURF student to the list of contaminants?

God bless them, they are keen but they usually manage to contaminate something when they come into the lab.

Yes we can, and we can also add contaminated stocks.

(gsovak, I am sorry, too cynical, that comes with the job)

well I guess the most common source of infection are bacteria

I like the speedy ones, that zoom through the culture (whatever type that is)

yeast you will most likely get, when you touch your hair with the gloves (or place your 'Hefeweizen') next to the flow

contaminated stocks are usually contaminated with one of the things you have listed already though.

Last time I did have a contamination (fungal) , Fungizone (Amphotericin B) did a good job cleaning up the problem

In our cultures this is seasonal, yeast in summer, mold in winter. Only the bacteria don't seem to care.

Recently I've noticed fungal contamination, but it won't show up in all of the plates. 1 plate will have it while all the others show no sign of contamination. Has anybody else experienced this?

My favorite are the guys who form the nice spongy looking blobs.

On the serious side for a moment, I've found that a 3% bleach solution for 15 min followed by a 1hr soak in ethanol kills anything that was in the dish. The next culture session I'm scott free of any goobers.

I'm always policing the shared incubator for violators who like to leave dessicating culture dishes around for many weeks just letting the fun guys (play on words, get it? ha!) spread their seed round the world...and into my cultures!

I wonder if the seasonal fungus is an east coast/ wet weather pheonomon. Never had any issues with seasonal contaminants in good ol usually sunny socal.

Oh, and vanishing, I love the guys who zoom around. If you look closely you can moving parts, flagella and whatnot at higher mag.

Last August my 293T cells were not packaging well and they were turning the media yellow very quickly. It ended up being mycoplasma which we tested for using the Roche kit (cat#11296744001) which is very good because it tells you the specific species you have. Luckily our stocks were not contaminated. However we had some primary cells from patients that were also contaminated and we tried to treat those but we ended up having to throw them away. Now we test periodically to make sure our cells are not contaminated. I think all labs should test periodically because there may not be any signs of the contamination and it can affect the outcome of experiments. The Roche kit is very simple it just takes a couple days (not time intensive, just lots of incubation). I would really encourage everyone to test for it.

I’m not sure if it is the suitable threat, but it is my first post here, sorry guys if I’m in the wrong place…
I have a question about cell culture contaminations; I can’t identify what have affected my fibroblast culture recently. It is very strange to me.
I check my cells after 24h of tripsinization and them were really well and growing fine and 24h later the medium was…black!! and all my fibroblast (6 plates) were dead. I put a sample of the medium I have used to grow in the incubator and it has had the same evolution, after 24h it was perfect and nothing was visible on it, but 24h later it was black and a lot of small aggregates, similar to sponges, were floating on it. The pH is near 11 (!) I use DMEM with 1% streptomycin and penicillin, 1% Pyruvate and 10% BS.
I want to know if it can be a fungical or yeast contamination. Now, I have only one aliquot of this fibroblast and as they were frozen the same day I tripsinized the contaminated dishes, I assume they are contaminated too. Before unfrozen it, I want to know if I can make them grow in antifungical or nystatin supplemented medium and what would be the best option. Usually, I unfroze my cells without antibiotic but this time I think I’ll make an exception.

Thank you very much, indeed!
Roser

HI Roster,
Welcom to scientistsolutions.com
It would have been better if you would have put this post in a new thread but it is more then OK that you have posted it.
So to begin with it seems that your medium is contaminated it is difficult to say with what as we can not see how it looks like and by trying to say what it is just because it is black it would not be scientific.
But, I guess that it would be some kind of Fungi .
Try some other bottles that arrived in the same batch.
I would start the frozen aliquot in the presence of anti fungal . I would do it in a 75ml flask that is closed with a cap. then sterilize the hood to minimize farther contamination. You can use Amphotericin B from Streptomyces sp. which is good for both Fungi and Yeast although I do not think that it is yeast as I can not recall that I have seen media becoming black after yeast contamination.
You can send us a post with a pic. of the black media maybe someone seen it already
Guy

Thank you very much Guy for your kind replay. I have cleaned all the whole room, the incubators, the hoods... And now I'm growing different samples of medium with different aliquots of BS to determine if them are clean or not... before using them or trashing everything...
I have a shot of my black medium and I'll upload it as soon as possible... I couldn't take a shot of the "alien" because the microscope with a camera is outside the culture room, in another floor... And I didn't want to scatter the "alien" by all the building... :-(
I think I'll try with this Amphotericin B.
Thank you!!
Roser