non-heat sterilization - suggestions?

K.G. Korth kkorth at
Thu Oct 12 11:18:54 EST 1995

gstuart2 at sol.UVic.CA (Gregory Stuart) wrote:
>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 reused. Does anyone have any brilliant (heck - any)
>suggestions! ...  :)
>Greg Stuart	gstuart2 at

We too use those trays and though we don't "sterilize" them per se, we 
have found a way to disinfect them that has been fairly successfull.

We clean out the trays, as you do, and then spray them with 70% isopropyl 
alchohol and then put them in a laminar flow biohazard safety cabinet 
with the UV lights on for an hour, minimum, to dry and to get UV 
irradiated (the inside of the trays toward the UV).  With the UV light 
still on, we reclose the trays and then use them.  We rarely see 
contamination from the re-used trays.  The UV does discolor the plastic 
over time, but it is still cheaper to replace them once every few months 
than every use.

I hope that helps.

Kimberly-Clark Corp.
Neenah, WI 54956
E-mail: kkorth at

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