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Preparing media with different pHs - (Jul/17/2011 )

Hi all,

I want to prepare an enriched media with different pHs in a large range (3-11). I have looked at several papers, but most remain ambiguous about details. Is there a standard method available for adjusting media pH?

I plan to autoclave the media first, then adjust with concentrated acid or base (5 M HCl or 5 M NaOH). Is this a good way to go about it? Do I need to filter sterilize concentrated acid/base or is it sterile already (being such extreme pH). I worry because the acid might dissolve the filter and mess things up.

Thanks.

-thc-

thc on Sun Jul 17 23:30:42 2011 said:


Hi all,

I want to prepare an enriched media with different pHs in a large range (3-11). I have looked at several papers, but most remain ambiguous about details. Is there a standard method available for adjusting media pH?

I plan to autoclave the media first, then adjust with concentrated acid or base (5 M HCl or 5 M NaOH). Is this a good way to go about it? Do I need to filter sterilize concentrated acid/base or is it sterile already (being such extreme pH). I worry because the acid might dissolve the filter and mess things up.

Thanks.

Hola, to me the best way could be add a buffer.As TB for E.coli has 0.1M phospate ph 7 or 7.5, you could prepare 0.1M PO4H2K and 0.1M PO4HK2 and mix in different proportions to get the wish pH, in any forum or any protocols page you will find tables, but Im not sure that this strategie gets the extrems pHs that you want. Buena suerte

-protolder-