1.When I autoclave media should I close the cap tightly or slightly?
I put all tools in plastic bag when I autoclave, should I close slightly the plastic and when it finish I close tightly the plastic? The air steam need to go inside the bag?
I read some document told me autoclave 21 minute, but in my lab everyone operate 35 to 40 minute, What you think?
Thank for your help.
For the media bottle, it is better to keep the cap a bit loose to avoid to pressure inside the bottle. A good way is to had autoclaving tape on the side so that it is clear that the bottle has been autoclaved. As Chris mentionned below once autoclaved, use gloves, and close the bottle firm after you open the autoclave and do not wait until it has cooled down completely.
It is not really important if it is slightly to tightly close. In fact you could have them on a tray or a bucket that would be fine to. One caveat is that it might depend on the equipment, the rules regarding the usage of the equipment etc. You would need to check these questions with a Senior person on the site.
The longer the better. If everyone operate at 35-40 min either there is a good reason to do so (often the case) or not. To be safe, I would suggest to be conservative there. Often what might happen is you want to make sure that you have the sample autoclaved at the highest temparature for at least 20 min. Because of leakages or other factors it might be best to leave it longer to make sure it is autoclaved at least 20 min.
Hope that helps!
