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:

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 I´m not sure that this strategie gets the extrems pHs that you want. Buena suerte

-protolder-