Pasteur's Experiment
Posted: 23 Jul 2008, 13:02
Hi All,
A teacher is doing Pasteur's Exp. this week, and this is the first time I have set it up. I have been reading other forums on the subject, but most related to the type of equipment used, and different set up techniques. My teacher has requested large test tubes, cotton wool(to stopper the tops)and the straight and s-bend glass tubes(these will pass through the cotton wool). I have two questions,
1: I noticed other people suggested using conical flasks, and rubber stoppers. Would those set-ups work better?
2: There has been no mention anywhere of sterilization. Do you have to sterilize everything first(that seems a waste of time with students then assembling things) or do you sterilize the assembled test tubes after, and if so, how? Or is there no need to sterilize?
We will be using a nutrient broth in the test tubes, covering them over using the different methods(cotton wool and glass tubes) and then seeing which ones go cloudy, which stay clear. I can't see our method working too well, my teacher is open to better ideas, and I would like to set up a prac that gets good results. Any help or suggestions on how to do this prac, particularly the sterilization bit, would be very gratefully recieved.
Many thanks in advance,
Cheers,
Lisa
P.S. I'm not a big fan of pressure cookers
A teacher is doing Pasteur's Exp. this week, and this is the first time I have set it up. I have been reading other forums on the subject, but most related to the type of equipment used, and different set up techniques. My teacher has requested large test tubes, cotton wool(to stopper the tops)and the straight and s-bend glass tubes(these will pass through the cotton wool). I have two questions,
1: I noticed other people suggested using conical flasks, and rubber stoppers. Would those set-ups work better?
2: There has been no mention anywhere of sterilization. Do you have to sterilize everything first(that seems a waste of time with students then assembling things) or do you sterilize the assembled test tubes after, and if so, how? Or is there no need to sterilize?
We will be using a nutrient broth in the test tubes, covering them over using the different methods(cotton wool and glass tubes) and then seeing which ones go cloudy, which stay clear. I can't see our method working too well, my teacher is open to better ideas, and I would like to set up a prac that gets good results. Any help or suggestions on how to do this prac, particularly the sterilization bit, would be very gratefully recieved.
Many thanks in advance,
Cheers,
Lisa
P.S. I'm not a big fan of pressure cookers