agars

Austin Reade rbs at nospam.hfx.andara.com
Fri Jul 6 00:40:16 EST 2001


lamb <L.A.M.Buisman at chello.nl> wrote in message
news:3B44D7EC.5CD98848 at chello.nl...

> Do you happen to know why is it that according to the handbooks agar
always has to be
> dissolved by boiling before autoclaving?

Is it possible that commercial agars available today are manufactured to be
more easily dispersed after direct autoclaving than agars available years
ago?  In the dim and distant past I seem to remember that it was quite
difficult to disperse the agar component if you autoclaved it without prior
mixing and heating.  A lump of agar with a gelatinised outer skin and poorly
hydrated centre would tend to form in the bottom of the flask.  Once this
experience is embedded in ones brain it then becomes one of the protocols
noted by Dr. Evdokimov.

One lab I worked in routinely used a microwave to prepare selective agar
media which didn't require sterilization.  With some practice one could set
the time to obtain a boiling solution without boilover.  However the colour
of the inside of the microwave attested to many failed experiments before
this happy state was reached.


Austin Reade
Reade BioSciences Inc
Halifax,NS, Canada






More information about the Microbio mailing list