runny agar

From: Mark T. Bachelor (bachelor@gateway.mggs.vic.edu.au)
Date: Thu Sep 18 1997 - 23:19:54 PDT


Date: Fri, 19 Sep 1997 16:19:54 +1000
From: "Mark T. Bachelor" <bachelor@gateway.mggs.vic.edu.au>
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg3592$foo@default>
Subject: runny agar

Greetings Carl,

Although I am not ingaged in TC I do work a lot with agar. The various
culture media in my recipe manual all have between 12 g and 30 g of agar per
litre (15g/L for fern gametophyte agar). It is also usually best to add the
agar, while stirring, when the water reaches at least 95 oC as it melts much
easier and reduces the risk of sorching and lump formation.
I would double check your quanities as runny agar is not usually desirable.

>The last 3 batches of media I have made have had the consistancy of runny
>pea soup when cooled. I'm not sure what I'm doing wrong. I have made the
>same media successfully 2 or 3 times previous with no problems. The other
>times, I made it 500ml batches, no problem, the last 3 batches were 1 litre
>batches. I can't believe that making 1000ml instead of 500ml is going to
>do that unless my agar measurements are out of line! Anyway, here's the
>mixture, any help would be greatly appreciated.

>1/2 strength MS Salts 2.2g/L
>6g/L agar
>25g/L sugar
>1000 mL distilled water

Regards

Mark T Bachelor
Biology Technican
Melbourne Girls Grammar School Voice: 9866 1676
South Yarra, Victoria, Australia Fax: 9866 5768



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