skim milk agar
Kimberly Walker
How in the world do you make this stuff? I tried to filter sterilize the
skim milk, but it wouldn't go through the filter. Autoclaved milk
carmelizes. Does anyone have expeience with this?
Kim
Irka
In article <Pine.SGI.3.91.970314...@umbi.umd.edu>,
Kimberly Walker <wal...@umbi.umd.edu> wrote:
Skim milk medium powder is available commercially ( Difco? I forget - I'm
not at work right now!), and I have prepared it by autoclaving with no
problems. I'm sure that you could just add agar and autoclave to make the
skim milk agar that you require.
--
Irka
GS
Kimberly Walker wrote:
>
> How in the world do you make this stuff? I tried to filter sterilize the
> skim milk, but it wouldn't go through the filter. Autoclaved milk
> carmelizes. Does anyone have expeience with this?
>
> Kim
Pasteurisation?
Try using commercial ultra-heat treated skim milk and add it aseptically
to the sterile molten agar - just like making blood agar.
Tony Stott
>
> > How in the world do you make this stuff? I tried to filter sterilize the
> > skim milk, but it wouldn't go through the filter. Autoclaved milk
> > carmelizes. Does anyone have expeience with this?
> >
> > Kim
>
> not at work right now!), and I have prepared it by autoclaving with no
> problems. I'm sure that you could just add agar and autoclave to make the
> skim milk agar that you require.
>
> --
> Irka
Make double strength Nutrient Agar, and double strength skim milk,
autoclave the NA at 121C for 15mins and the milk at 116C for 20 mins,
cool both to 50C, mix and pour plates.
PS slowly add the water to the milk powder with constant stirring so you
don't get lumps.
--
Tony Stott
Department of Microbiology,
Monash University, Clayton, 3168, Australia
Jan Hoolwerf
Hello,
Kimberly Walker <wal...@umbi.umd.edu> wrote:
KW> How in the world do you make this stuff? I tried to filter
KW> sterilize the skim milk, but it wouldn't go through the filter.
KW> Autoclaved milk carmelizes. Does anyone have expeience with
KW> this?
We routinely use Plate Count Agar (PCA, Difco i think) with 5% skim milk made
from spray dried milk powder.
Just dissolve the milk powder (or the equivalent amount of milk made from
this powder) in the agar before sterilising and steam sterilize 15 min. 120 °C
as usual.
In this concentration you will not notice carmelization and what we use is an
official method in the Dutch dairy industry.
with regards, Jan Hoolwerf
******************* these words were mine, all mine !! ********************
J.D. Hoolwerf
Neth. Inst. for Dairy Research
P.O. Box 20 phone : 31-318-659511
6710 BA Ede fax : 31-318-650400
the Netherlands e-mail : hool...@solair1.inter.nl.net
***************************************************************************
Jan Hoolwerf
Hello,
Tony Stott <Tony....@med.monash.edu.au> wrote:
TS> PS slowly add the water to the milk powder with constant stirring
TS> so you don't get lumps. --
It's the other way around: slowly add the milk powder to the water with
constant stirring.
Roy Markussen
Try adding Bacto Skim-milk (Difco) at 0,1% to standard Plate Count Agar.
This will give you skim-milk agar for analysing total count in milk
products.
--
Roy Markussen
Næringsmiddeltilsynet i Tønsberg
Tonsberg Public Food-control, Norway
http://www.miclis.no/nmt/tonsberg
Kimberly Walker <wal...@umbi.umd.edu> skrev i artikkelen
<Pine.SGI.3.91.970314...@umbi.umd.edu>...
>
> How in the world do you make this stuff? I tried to filter sterilize the
> skim milk, but it wouldn't go through the filter. Autoclaved milk
> carmelizes. Does anyone have expeience with this?
>
> Kim
>
>