culture contamination

Wolfgang Schechinger wolfsc at ibms.sinica.edu.tw
Wed Mar 28 03:02:12 EST 2001


maya, 

why crossposting to so many groups?
when methds-reagnts knows answers to all problems?

letzee...

are there antibiotics present and which? Do you buy premade media or 
are you using home brew? are you sure that yor cell stock is not 
contaminated?

it is most likely that you host some bacteria in your culture, you'll 
recognize them as small statistically moving dots (lots smaller 
than cells). if your media turns yellow, then there is plenty of 
them.  (they eat up all the glucose and produce acidic metabolites). 
if media is even opaque, then there are most likely yeasts (which 
won't be affected by PenStrep). other cause might be mycoplasms, but 
they are most likely invisible by light microscopy. use DAPI or 
H33258 staining to detect them by fluorescence microscopy or use a 
dedicated kit for immunocytochemistry or PCR 
you might ask an ecperienced colleague to have a look on your 
cultures,that will save  lots of time and hassle.

If your cultures are not especially unique and precious, discard 
them and use fresh cells from stock.
in order to check where contimation originates from, you might 
consider incubating medium inoculated with aliquots of any solution  
for some days.

Good luck, 
Wolfgang

PS feel free to ask more if this info is not enough to track doewn 
the problem.

> From:          maya <maya-khorchide at bigfoot.de>
> Subject:       culture contamination
> Date:          Sun, 25 Mar 2001 11:54:26 +0200
> Organization:  Vienna University, Austria
> To:            ageing at hgmp.mrc.ac.uk, bio-info at hgmp.mrc.ac.uk, bioforum at hgmp.mrc.ac.uk,
>                cellbiol at hgmp.mrc.ac.uk, immuno at hgmp.mrc.ac.uk, methods at hgmp.mrc.ac.uk,
>                microbio at hgmp.mrc.ac.uk, neur-sci at hgmp.mrc.ac.uk, proteins at hgmp.mrc.ac.uk

> 
> I am working with cell cultures and it seems that I have a contamination
> problem.
> Under light microscopy dark dots are visible in the cells and are likely
> to be also moving on their surface. Cell growth, attachment and
> viability are affected.
> These mysterious creatures are only observed in association with cells
> but not in incubated cell free medium.
> Years ago only some cultures were involved but now the infection is
> worsening and spreading about other cultures.
> If you have an idea who these intruders could be or have an advice how
> to recognize them or get rid of them please help me.
> 
> MAYA
> 
> 
> 
[tiss mezzage wahs broduceRd using TYPO GENERATOR zoffwer]
-----
Dr. Wolfgang Schechinger
Lab N233 (c/o Dr. Steve Roffler)
Institute of Biomedical Sciences
Academia Sinica
128 Yen-Chio Yuan Rd. Sec.2
Taipei 115
Taiwan R.O.C.
Tel +886-2-2798-9152
Fax +886-2-2782-9142
Mobile +886-925-136893
wolfsc at REMOVETHESEANTISPAMCAPITALSibms.sinica.edu.tw
-----

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