Sterile methods

Randy Willis willis at
Fri May 23 19:25:06 EST 1997

> Wilson wrote:
> >
> > Dear all,
> > I would like to know why some chemical reagents can be steriled by
> > autoclave while some of them should sterile by filteration only ie
> > CaCl2, MgCl, Glucose, etc.


I'm not sure where you got your examples, but these particular ones are
wrong.  I have regularly autoclaved solutions of 1M CaCl2, 1M MgCl2 and
20% glucose.  The only thing about glucose is that you cannot autoclave
it in the presence of salts or it will caramelize (sp?)...I've done it
and your solution goes a lovely amber colour.  This is not to say that
there are not solutions which are heat labile.  Antibiotics, protease
inhibitors and the like should all be filter-sterilized wherever
possible.  For many, it is like baking.

Good luck and keep your eyes open.

Randall C Willis, Researcher
Biochemistry, Hosp for Sick Children
3522-555 University Ave.
Toronto, ON

416-813-5933 (ph)  -5022 (fax)

willis at

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