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skim milk agar
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Sue Katz
May 15, 2016, 1:31:19 PM5/15/16
to met...@oat.bio.indiana.edu
When I make skim milk agar to observe casein digesion by bacteria, I make the agar part up at 20 % less volume than requested (400 ml if I am going to make 500 ml)
I separately autoclave 20 % skim milk (off the shelf, carnation or private label usually); I do at least twice as much as I think I am going to need. I don't shake it up, but I do make sure it is
dissolved before autoclaving. After autoclaving, I temper the agar to about 50 C, then add the cooled milk, mix and pour plates. There will be some coagulation, I don't know myself how to entirely get rid of it.
Every once in a while, the milk just doesn't work, and I buy a new package (store in refrigerator or room), and it works again.
The milk should not be browned, it should still be creamy white colored after autoclaving and use.
Milk does coagulate when autoclaved at 121 degrees, 15 lb per inch; If you have an autoclave that will go lower, then it should work at the next lower setting (a little longer time)
I don't think filtering will work because of the colloidal proteins.
Sue Katz Amburn
Rogers State University, Claremore OK, US
________________________________________
Date: Fri, 13 May 2016 18:09:27 +0000
From: "MacGregor, Barbara" <bmac...@unc.edu>
Subject: Skim milk agar hints
Hi,
I’ve never made it, but found a collection of hints on Research Gate. Maybe the answer is here? (Scroll down to Claudia Schinke’s answer, that seems to be the most complete).
https://www.researchgate.net/post/Does_anyone_understand_how_to_make_skim_agar_media
Barbara
From: <sairah...@gmail.com>
Subject: Query about skim milk agar
Date: 12 May 2016 16:27:00 GMT-4
To: <met...@net.bio.net>
On Friday, March 14, 1997 at 1:00:00 PM UTC+5, 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?
I am also making skim milk agar with 1% tryptone... before autoclaving it is prooperly dissolved and is clear solution...but after autoclaving there are clots of milk in media and the solution is not clear and properly dissolved, although it solidifies...Kindly guide where i am doing the wrong?
I separately autoclave 20 % skim milk (off the shelf, carnation or private label usually); I do at least twice as much as I think I am going to need. I don't shake it up, but I do make sure it is
dissolved before autoclaving. After autoclaving, I temper the agar to about 50 C, then add the cooled milk, mix and pour plates. There will be some coagulation, I don't know myself how to entirely get rid of it.
Every once in a while, the milk just doesn't work, and I buy a new package (store in refrigerator or room), and it works again.
The milk should not be browned, it should still be creamy white colored after autoclaving and use.
Milk does coagulate when autoclaved at 121 degrees, 15 lb per inch; If you have an autoclave that will go lower, then it should work at the next lower setting (a little longer time)
I don't think filtering will work because of the colloidal proteins.
Sue Katz Amburn
Rogers State University, Claremore OK, US
________________________________________
Date: Fri, 13 May 2016 18:09:27 +0000
From: "MacGregor, Barbara" <bmac...@unc.edu>
Subject: Skim milk agar hints
Hi,
I’ve never made it, but found a collection of hints on Research Gate. Maybe the answer is here? (Scroll down to Claudia Schinke’s answer, that seems to be the most complete).
https://www.researchgate.net/post/Does_anyone_understand_how_to_make_skim_agar_media
Barbara
From: <sairah...@gmail.com>
Subject: Query about skim milk agar
Date: 12 May 2016 16:27:00 GMT-4
To: <met...@net.bio.net>
On Friday, March 14, 1997 at 1:00:00 PM UTC+5, 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?
I am also making skim milk agar with 1% tryptone... before autoclaving it is prooperly dissolved and is clear solution...but after autoclaving there are clots of milk in media and the solution is not clear and properly dissolved, although it solidifies...Kindly guide where i am doing the wrong?
askint...@gmail.com
May 27, 2016, 7:15:08 AM5/27/16
to
15 Mayıs 2016 Pazar 20:31:19 UTC+3 tarihinde Sue Katz yazdı:
Dear friends. You should autoclave the milk separately.After autoclave, you can add to the medium. Also, if your medium consist salt ( or high pH) , it may be harmful for milk.
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