Chris,
I grow AX2 cells in shaken suspension at 22oC in HL-5 medium (10g dextrose, 10g proteose peptone, 5g yeast extract, 0.97g Na2HPO4, 0.48g KH2PO4, and 0.03g streptomycin, volume to 1 liter and autoclaved) and the doubling time is around 11.5 hours. It remains constant for about 96 hrs from the start of the culture.

I do not know if the dish washer detergent is the problem but I always hand-wash flasks  with 1% alconox and autoclave.
Sometimes irregular growth is due to some kind of contamination which you can not see but it kills cells slowly or causes them to grow slowly leading to irregular growth rate. I would suggest starting the culture from the fresh stock culture.

I hope it helps.

Sandhya.

Dr. Sandhya N Baviskar
Assistant Professor
Department of Biology
University of Arkansas- Fort Smith
5210 Grand Ave.
Fort Smith AR 72913
Phone : 479-788-7789
________________________________________
From: DICTY [[log in to unmask]] On Behalf Of Christian Hammann [[log in to unmask]]
Sent: Wednesday, July 21, 2010 9:43 AM
To: [log in to unmask]
Subject: [DICTY - 368] Axenic growth of AX2

Dear all,

since more than two months we observe very irregular growth of our
wild type AX2:
the doubling time varies as it seems at random between 10 and more
than 40 hours.

All the usual parameters including temperature, medium (we use
Formedium HL5 medium with glucose), water, residual detergent in
flasks from the dish washer, pH, light or culture density have been
checked and they all do not seem to be the reason for this behavior.

My questions are the following:

Is this also observed in other labs?
What is the usual doubling time of AX2 in your hands?
How constant is that doubling time?
How many of you have tried to supplement the medium with vitamins, as
stated in the technical comments on Dictybase, and how successful was
that?

Your input is much appreciated,

Chris


Christian Hammann

Heisenberg research group ribogenetics

Faculty of Biology

Technical University Darmstadt

Schnittspahnstr. 10

64287 Darmstadt

t +49 6151 – 16 3955

f +49 6151 – 16 7440

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