SOB Medium: Why add Mg late?

[Jeff Lawrence]

In article <3tg6g3$ov5 at griffin.ccc.nottingham.ac.uk>, Nigel Kenward
<mbxnjk at vax.nott.ac.uk> wrote:

> I understand that if you put the Mg ions in prior to autoclaving, there 
> is a risk that the Mg will precipitate out and make the solution cloudy.
> I've never risked it so I can't confirm whether it's true or not !
> Nigel Kenward

this is, for the most part, true.  Mg++ requires a chelating agent, like
citrate, to stay in solution at high temperatures.  without it, it's
likely to precipitate and it's murder driving it back in.  believe me, i
know.

jeff

-- 
jeff lawrence
lawrence at bioscience.utah.edu