Re: Steam sterilization of vessels in autoclaves:
Some options, views and potential alternative strategies;-
If available, it might be worth considering use of a hot air oven.
Then you obviously need not worry about air removal and
condensate removal. I'd let them cool to, or close to, ambient
before removing the items so as to lessen the risk of them
"sucking" in non-sterile air. A foil top with generous overlap (or
oven proof screw cap) should prevent subsequent
recontamination.
If a few mL of water would be acceptable in the containers, that
could be the way to go. A tight seal (eg. screw cap) could then be
applied and the steam would be provided internally (as for a
sealed ampule/vial) and air removal/ingress issues go away.
If neither of the above are viable options, we have successfully
used Tyvek as a cover for openings. It has sufficient porosity to
prevent build up of a differential pressure yet has good (and
documented) microbial barrier properties. You might need to add
some pre-vacs to your cycle, but that's not unusual in such
cases. As with the oven, I'd let them cool in the autoclave as close
to ambient as possible before opening the door.
I have seen bottle tops with built in replaceable vent filters but
can't recall the supplier.
With any of the above approaches, you may be asked to support
any given shelf life for the sterilized containers.
Regards,
Gerry.Morris@Americas.Nycomed.com
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