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.....













