microcentrifuge tubes autoclaving - Sterilization techniques (Feb/23/2010 )

hi
we all commonly autoclave microcentrifuge/eppendorf tubes prior to use (just to be on the safe side!!!) despite the fact that they come in sterile packing.
Usually we keep the tubes openi in the canister for autoclaving. One of my very old and wise professor says the tubes must be closed...when we open the canister to take out the tubes (even if its aseptically in a hood) exposes all the open tubes as we might not require to use them all at once. His argument is steam penetrates the polypropylene and leaving them closed is safe when the canister or container has to be opened.... theres lesser exposure of the tubes (as they are closed). Though common practise makes us feel more at ease to leave the tubes open during autpoclaving.... he does have a point.... even if its an old school of thought.

Does anybody have a similar/different opinion? I want to agree with him but I am not sure whether it seems right.....

In my lab, we stored the closed tubes in the box and then autoclaved. It's okay. After autoclave, keep in dry oven. I don't think it's good to open the cap.

We've never had problems with leaving the tubes open. When I have purchased presterilised tubes, I used them straight out of the package with no trouble.

we autoclave the tubes, with their lids open and in closed boxes.............works absolutely fine...

we autoclave with lids open so that if there is something inside the tubes, they can be autoclaved well.

for normal purpose you dont need to autoclave tubes. Only take care if you wish to use them for cell culture.

thanks all.... i guess wats more important is that the autoclaving and the use of the autoclaved tubes is done properly.... leaving them open during autoclaving does make more sense after all.