non-heat sterilization - suggestions?

Francisco G da Nobrega ib - bio 7588 fgdnobre at
Fri Oct 13 09:21:49 EST 1995

On Thu, 12 Oct 1995 U12201 at UICVM.CC.UIC.EDU wrote:

> Rinse with a powerful detergent (RBS35 or PCC54 or similar)
> - then dip overnight in 70% ethanol.
> In article <1995Oct11.050808.23799 at sol.UVic.CA>, gstuart2 at sol.UVic.CA (Gregory Stuart) says:
> >
> >Hello. We use big plastic trays (25cm^2) for plating E. coli and lambda
> >phage. They are rather expensive (circa $5 ea.), and we use a lot of them.
> >I need a method of sterilizing them, after they have been cleaned, for
> >reuse. They cannot be autoclaved. Does anyone have any brilliant (heck -
> >any) suggestions! ...  :)
> >
I have been using a simple procedure to sterilize plastic ware (like 
Petri dishes) because here it is still expensive to discard them. I got 
the tip from the way surgeons sterilize optical instruments needed during 
operations. Place the stuf in a glass or plastic box with a lid that 
closes well. Plastic itens could be inside plastic bags that are left 
open. Leave inside the container an open dish with about 3 spoonfuls of 
paraformaldehyde (a solid powder that will release formaldehyde vapors).
Keep the container closed at least overnight. Then seal the plastic bags 
and store the plates until needed. I like to store then in the bags for a 
few days or one week to allow ample time for the residual formaldehyde to 
go away.

				F.G. Nobrega
				Biologia -IBUSP
				Universidade de Sao Paulo SP BRASIL
E-mail fgdnobre at

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