Re: TC, Microwaves and Pings

From: Peter Cole (carnivor@flytrap.demon.co.uk)
Date: Fri Apr 11 1997 - 07:09:21 PDT 

Date: Fri, 11 Apr 1997 14:09:21 GMT
From: Peter Cole <carnivor@flytrap.demon.co.uk>
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg1387$foo@default>
Subject: Re: TC, Microwaves and Pings

       Catching up on old digests - sorry for the response-lag.

SCHLAUER@chemie.uni-wuerzburg.de writes:
> Dear Neal,
>
> > I do not own a pressure cooker for which I need to sterilize media for
> > tissue culture. I was wondering if I could use my microwave oven to
> > sterilize the media? If I can, how long?
>
> The answer is a clear NO. Microwave ovens do only (almost exclusively)

       Sorry Jan, but I have to disagree - I microwave all my media because
       it's easier and my flasks are polypropylene (ie: melt in the PC - I
       bleach-sterilise them instead and fill them from the jug I cook the
       medium in,) and it works just fine (99.7% success to date filling on
       an open bench.) But don't just take my word for it - check out:

            Lundergan, C. and N. J. Wood. 1981. Microwave sterilisation of
            tissue culture media. HortScience 16:417

       So long as the medium is heated to between 100'C and 121'C for 2-4
       minutes it will be effectively sterilised (don't forget, it is only
       the wet stuff that goes into the flasks, and that's been heated
       sufficiently to kill anything floating around in it - it's not like
       you're scraping stuff off the walls of the m/wave that might
       admittedly still be contaminated.)

> heat liquid water (would you touch a cup of coffee heated in the MW
> oven if the cup was heated as well?). Therefore, the MW oven is not
> able to sterilize any spores (containing almost no water at all)
> which contaminate your tc media and equipment. As some spores may
                                      ^^^^^^^^^
       Indeed - DO NOT sterilise metal foreceps etc. in the m/wave unless
       you want a rather impressive but very expensive (not to mention
       quite dangerous,) indoor forework display!

         Hope this helps,

                       Peter

__________________________________________________________________________
Peter Cole,Cambrian Carnivores,::Carnivorous Plants and seeds for sale -
17,Wimmerfield Crescent,Killay,::http://www.flytrap.demon.co.uk/cchome.htm
  SWANSEA SA2 7BU, WALES, UK ::mailto:carnivor@flytrap.demon.co.uk
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