[Drosophila] Re: culture problems

Mark Thorson via dros%40net.bio.net (by nospam from sonic.net)
Tue Sep 4 17:17:59 EST 2012


dr julien colomb wrote:
> 
> The fact that the adults die and not the larvae is peculiar.
> I never had that before, but it reminds me of a story with pesticides.
> In my former labs, we had to change the corn because the one we used was
> not produced anymore. We took bio-cornmeal and flies started to die: the
> corn was not insecticides free... Maybe you have such a problem?

Beginning with my 8/24 batch, I switched to organic
bananas.  Productivity of my cultures seems about
the same, though I've only noticed two examples of
early adult death.  In both cases, the medium
developed a creamy or melted cheese appearance on
top, which I believe indicates bacterial overgrowth.

My suspicions about carbon dioxide accumulation are
in doubt.  I now think the stinging odor is acetic
acid.  It does not seem to be associated with poorly
productive cultures.

I think my earlier suspicions about bacteria being
the main problem might be correct.  I'm thinking
that I need to consider ways to eliminate possible
sources of contamination.  I do wash all of my
equipment with hot water and detergent, but I
had not been doing anything with the disposable
plastic cups I use as culture vessels.  I was
assuming they were sanitary fresh from the package.
I'll start chemical sterilization with hydrogen
peroxide on the cups and see if that has an effect.



More information about the Dros mailing list