"J.Rowlands" <oss004 at bangor.ac.uk> wrote in message
news:3A94FB2F.24ECDD3A at bangor.ac.uk...
> G'day all,
>> I've a student trying to get to grips with milk agar for a protease test.
> It's a long time since I did this! References suggest autoclaving
> milk-powder solution, but this seems dooomed to failure with heat
> denaturation.
>> Anyone currently engaged successfully in milk agar that can give advice
> will become our lab hero for the week!
>> Many thanks,
> John Rowlands,
> University of Wales, Bangor.
> --
Might it be easier to buy it ready made? If it's the same as what's used for
testing heat treated milk milk samples then Oxoid make it as a powder (it's
in the Fisher microbiology catalogue). Dunno if that's any more reliable.
Failing that, have you tried pressure cooking it at lower pressure? Or (as
another random thought) you could always make up the milk solution, sonicate
it to sterilise, and then add that to the rest of the medium?
Failing that, might there be any mileage in using adifferent protease type
medium? I seem to remember a really nifty paper by Wirth and Wolf (or Wold
and Wirth) on a blue-dye linked casein that could be used in plates.