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Anyone interested:  I have 2.5 bottles of Difco proteose peptone from
the 80's, stored cold since then, if anyone would like them. Tell me
how to get them to you.

Although this would not work for everyone, I urge Tetrahymena workers
to at least try growth in the powdered-milk-based recipe of:
        Saliba, R, et al (1983) An inexpensive and practical medium for
rearing mass cultures of Tetrahymena.   Prostistologica 19:417-422.
My lab has used this medium exclusively for a long time; it's extremely
cheap, and the cell density is very high.  The powdered milk sold for
use in infant formula has a higher lipid content, and is iron
fortified: an admixture of this increases yield even more.  Our
modified recipe:

        -30 g   Non-fat powdered dry milk (Carnation, or equivalent)
        -  2 g  Infant milk-based powdered formula (Carnation 'Good Start' or
equivalent)
        -  4 g  Yeast extract powder
Add sequentially to 4 liters of distilled water while stirring; stir to
uniformity, aliquot and sterilize.  The medium is white and opaque to
start, but clears and yellows as the Tetrahymena inoculum grows in
density.

If you are not totally and terminally standardized on the traditional
proteose peptone recipe, this is worth a try.
(OK, granted that we are raising our Tets as food for Euplotes and
other carnivores -- but hey, there's an additional advantage that such
Tets are not toxic as Oxytrichid food, as they seem to be after growth
in proteose peptone.)

JOHN KLOETZEL


On Mar 31, 2007, at 5:26 PM, Kathy Collins wrote:

> We're hoping to switch proteose peptone sources to avoid backorder
> problems
> and save money.  Has anyone tried the crude proteose peptone from EMD
> Chemicals - 1.07229.1000 - for rapid growth media?
>


**JAK**

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John A. Kloetzel, Ph.D.
Associate Professor, Emeritus
Department of Biological Sciences
University of Maryland Baltimore County (UMBC)
1000 Hilltop Circle
Baltimore, MD  21250-0000  USA
Phone:  (410) 455-2247
Fax:  (410) 455-3857
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