autoclaving - a lot of fluid lost? (Aug/31/2009 )
Think about it - why should a (loose) cap loosened more lead to more boil over?
lab rat - I understand the "bottle larger than the amount of liquid" and I'm sure autoclaving a bottle smaller than the amount of liquid would be challenging. I just can't see many folks trying it. Have you?
What exactly is you reason for being on this forum, eberthella?? From what I can see, all you seem to do is go around insulting people and trying to cause trouble. The whole reason for the forum is for us to help each other out. We don't always have the right answers, and we don't always express what we are trying to say in the clearest and most accurate way. But at least we are trying to be helpful. Which is a heck of a lot more than can be said for you.
Sorry you're so sensitive. I could have just said you were wrong like George but merely asked you to think. Sorry if asking you to think is so offensive . I'll not make such a bizarre request again.
I actually wasn't talking about what you said to me, I was talking about your comment to labrat. It was abundantly clear to me (and I'm sure most others) what labrat was trying to say, and yet you still felt the need to be a smart-ass about it.
Not sure anything is abundantly clear to you, leelee, so let me help you. A vessel smaller than it's contents is an anolomy and lab rat is an adult. He or she doesn't need a person as inexperienced in the lab and selfconscious as you to speak for them. Understand?
Self conscious?? No. Inexperienced, well that is relative I suppose. But clearly I am wasting my time with this, eberthella.
I am not trying to make an enemy, nor get involved in a slinging match with anybody on this forum. The reason I visit is to learn, help when I can, and get help when I need it. It saddens me that there are people on this forum who use it as an outlet to insult and belittle others, all for what? To make themselves feel smarter?? Better?? Whatever. Your motivations for being that way are your deal. Good luck with that.
You will always lose some liquid after autoclaving due to evaporation. There are two solutions to this:
1) to minimize the amount lost, use a vessel at least twice the volume of your solution. You're doing 250mL, so use a 500mL flask or bigger. Use aluminum foil to cover the opening, tie with a string to prevent the foil from falling off after autoclaving.
2) as someone already suggested, filter-sterilize. This is the best option if you want to be very precise.
eberthella, please take your sarcasm elsewhere. Leelee is right, you are picking at small errors. Based on your inability to not drop the issue, I'm sure you will comment on this statement too. This forum really is to help, if you can't help then don't.
Back to the issue of autoclaving. When I usually autoclave something and require precise volumes I do as swanny mentioned - add the difference lost. Filter sterilize is also a good way if you are more confident of your reagent source and using a MUCH larger bottle than the volume autoclaved helps to reduce boil over as newbie99 said.
not to lose liquid, you should :
- as said Leelee : us a bigger bottle (it means use a 2L bottle to autoclave 1L of liquid and not a 1L bottle. (I add this explanation because it doesn't seem obvious to every body than talking about a bigger bottle is not always vs a bottle smaller than the volume)), so that the liquid will not boil out of the bottle.
- don't open too early the autoclave, let it cool down close to room temperature.
About opening more or less the cap : it has no influence on losing liquid (if it's open even a little, the liquid will go out in any way.
Stephan. My comments corrected errors offered by leelee and lab rat. You comment was useless - but thanks anyway for trying.