Sterilizing with alcohol?

Andreas Brune Andreas.Brune at uni-konstanz.de
Wed Dec 20 03:38:11 EST 1995

In article <4b7i7l$pna$1 at mhadg.production.compuserve.com>,
   Ben Feldman <103153.3041 at CompuServe.COM> wrote:
>I need to sterilize some electrodes.  If memory serves, a biologist 
>friend once told me that 70% alcohol works well as a disinfectant.  
>Is this true?  If so,
>(1) ethanol or isopropanol?
>(2) why 70% instead of 100%?

(1) Both should work, but I never used i-Propanol myself.
(2) 70% EtOH is supposed to be more efficient killing Gram + cells.
    The usual explanation is that 100% EtOH immediately dehydrates the
    murein sacculus which can be very thick with Gram + bacteria
    and then efficiently seals the cytoplasm from contact with the
    alcohol (seemingly logical but to my knowledge not published 
    anywhere ...)

If you are attempting to sterilize electrodes make sure to soak them
long enough to allow the sterilant to diffuse into any crevices. If you
are using filling solutions behind a sinter glas diaphragm regard this 
a possible contamination pathway as well.

Dr. Andreas Brune * Mikrobielle Oekologie * Fakult. f. Biologie * Universitaet Konstanz * Postfach 5560, M654 * 78434 Konstanz * Germany * Phone: +49-7531-883282 * Fax: +49-7531-882966


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