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Anno
Experimenter



Registered: 06/17/99
Posts: 24,168
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Penicillin and streptomycin in agar
#1223042 - 01/16/03 06:19 AM (22 years, 2 months ago) |
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Most mushroom growers and books will tell you, that you can?t add penicillin and streptomycin to an agar mixture before pressure cooking, since the pressure cooking destroys those antibiotics.
I found this only to be partially true.
After mobyd told me he was using it, I added a mix of both antibiotics to a PDYA in a concentration of 0.8 g per liter penicillin and 0.2 g per liter streptomycin and pressure cooked the agar for 30 minutes.
Then I inoculated 2 agar plates, one with the antibiotic mix, one without, but both having the same agar formula, with a bacterial contamination I had on another dish.
As you can see, the growth on the antibiotic dish is much less than on the normal dish.
Edited by Anno (01/16/03 10:41 AM)
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Raadt
nicht

Registered: 06/07/02
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Re: Penicillin and streptomycin in agar [Re: Anno]
#1223247 - 01/16/03 07:32 AM (22 years, 2 months ago) |
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I wonder if any other antibiotics that were deemed as useless can work? now i'm going to have to try it with some extra human antibiotics, that i have. Thanks Anno! =)
-------------------- Raadt
-- The information I provide is only information from readings, growing of gourmet mushrooms, and second hand stories--
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Hermes_br
~~~


Registered: 04/24/01
Posts: 546
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Re: Penicillin and streptomycin in agar [Re: Anno]
#1223543 - 01/16/03 10:24 AM (22 years, 2 months ago) |
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Thank you , Anno !!
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thescientist
Registered: 03/09/02
Posts: 810
Loc: Dade County
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Re: Penicillin and streptomycin in agar [Re: Anno]
#1223673 - 01/16/03 11:00 AM (22 years, 2 months ago) |
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Do any of the microbiologists think there could be an issue w/ producing antibiotic resistant bacteria. Could this be a health hazard? what do you think anno?
remember, this is not a microbio lab w/ iodine infused table tops and such. this stuff is being grown in closets. perhaps im being a little overcautious
pizza ow
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Anonymous
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Re: Penicillin and streptomycin in agar [Re: Anno]
#1223767 - 01/16/03 11:35 AM (22 years, 2 months ago) |
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I thought it was like some Plant growth regulators. You just have to add more, and are uncertain as to how much remains in the Media post sterilization.
Or you just add them post sterilization.
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Anonymous
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Re: Penicillin and streptomycin in agar [Re: thescientist]
#1223774 - 01/16/03 11:37 AM (22 years, 2 months ago) |
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I only use antibiotic agar as a last resort. If I can't get a clean culture of something wild.
Definetly should not be used regularly.
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Champion des Champignons
long standing member;)

Registered: 07/26/00
Posts: 2,681
Loc: Alba
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Re: Penicillin and streptomycin in agar [Re: Anno]
#1224083 - 01/16/03 02:29 PM (22 years, 2 months ago) |
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when making peroxidated agar, my mixture never gets above 100C, without any problems, ie I don't pc the mix before adding the H2O2. I'll bet if you tried that the antibiotics would stand an even better chance of survival...
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hmmm........
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viscid
dikaryon


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are you saying that you go without sterilizing your agar, yet things go well?
peroxide and no pressure cooking?
really? cooooooooooooooooool. can you enlighten me, or am i gonna get a link to rush waynes info?
human antibiotics, what will they think of next?
-------------------- You do not know me.
You can't see me.
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Anno
Experimenter



Registered: 06/17/99
Posts: 24,168
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Re: Penicillin and streptomycin in agar [Re: ]
#1224813 - 01/16/03 08:09 PM (22 years, 2 months ago) |
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>I only use antibiotic agar as a last resort.
Same here. Antibiotics shoudn?t be used on a regular basis, just if you encounter spores or a culture that are infected with bacteria.
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Zen Peddler


Registered: 06/18/01
Posts: 6,379
Loc: orbit
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Re: Penicillin and streptomycin in agar [Re: Anno]
#1224923 - 01/16/03 09:26 PM (22 years, 2 months ago) |
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And it works against bacteria alone. And ofcourse most bacteria are easier to isolate out of a culture than molds which are the usual nasties that show up from wild prints in my experience.
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cheesenoonions
??????????????

Registered: 04/01/01
Posts: 584
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Re: Penicillin and streptomycin in agar [Re: Anno]
#1225485 - 01/17/03 04:36 AM (22 years, 2 months ago) |
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I encountered a similar experience at work. We were trying to isloate bacterial transformants using ligated plasmids with ampicillin resistance genes. We made a batch of LB media and added amp. We then autoclaved the flask of about 1 L media forgetting that there was amp in it. We decided to use it anyway and the colonies that did grow were shown to have the resistance to ampicillin through restriction analysis. Non resistant cells did not grow on the media. So after autoclaving, the amp still worked.
Edited by cheesenoonions (01/17/03 04:37 AM)
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Champion des Champignons
long standing member;)

Registered: 07/26/00
Posts: 2,681
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Re: Penicillin and streptomycin in agar [Re: viscid]
#1226201 - 01/17/03 08:46 AM (22 years, 2 months ago) |
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yes, I just boil the agar mix in a pan for 5 mins, leave to cool to 125F, add the h202 and pour. No flowhood, no nothing, no contams.....well maybe 2 out of 100 plates, but this was probably due to dirty petris
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hmmm........
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ragadinks
MrBeatle


Registered: 10/20/03
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Quote:
yes, I just boil the agar mix in a pan for 5 mins, leave to cool to 125F, add the h202 and pour. No flowhood, no nothing, no contams.....well maybe 2 out of 100 plates, but this was probably due to dirty petris
Woow, can't believe that. How much H2O2 is added to the agar ?
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Anno
Experimenter



Registered: 06/17/99
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Re: Penicillin and streptomycin in agar [Re: ragadinks]
#2225369 - 01/07/04 08:21 AM (21 years, 2 months ago) |
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Jared
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Registered: 04/22/01
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Re: Penicillin and streptomycin in agar [Re: Anno]
#2225559 - 01/07/04 09:55 AM (21 years, 2 months ago) |
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Nice Tek!
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Jared
Stranger

Registered: 04/22/01
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Re: Penicillin and streptomycin in agar [Re: Anno]
#2225566 - 01/07/04 09:58 AM (21 years, 2 months ago) |
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<Hmm..> I imagine this could benefit honey water as well. If one were to add a potent amount of peroxide (far too much) so that it would eliminate the bacteria and mold spores, and then afterwards leave the mixture in direct sunlight so as to break down the peroxide.. one could sterilize the honey water without ever heating it.. avoiding possible caramalization altogether...? </Hmm..>
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ucsdmolpath
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Re: Penicillin and streptomycin in agar [Re: Anno]
#2230081 - 01/09/04 12:01 AM (21 years, 2 months ago) |
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hi all, a way to preserve the activity when mixing antibiotics into your agar is the following:
1) mix your agar media and autoclave as usual. 2) remove your sterilized media from the autoclave and let it sit on a cool countertop...as funny as it sounds, when the flask or vessel that your media is in is cool enough to touch it to your cheek, mix in the antibiotics. 3) pour ASAP and set as usual.
i have been in biomedical/mol. bio sciences for years, and after having been thru several years of bacterial cloning, i have almost never had contamination by doing it this way.
you can also pour your plates, set them, and using a flame sterilized glass spreader (made from a pasteur pipet or whatever), mix your antibiotics with a little distilled water to a volume of about 100?l. spread all over the surface and allow to dry with the lid cracked open. this is a surefire way to make sure your antibiotics work, however, less convenient than the make-sure-it's-cool-enough-by-your-cheek method)
hope this helps
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YidakiMan
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Registered: 09/28/02
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Re: Penicillin and streptomycin in agar [Re: ucsdmolpath]
#2760294 - 06/03/04 10:11 AM (20 years, 9 months ago) |
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I feel like a noob, bringing this thread back to life. Anyway, I am going to make some plates using clindamycin to finalize the life of some bacteria that have been giving me trouble. I had a tooth infection that ended in a root canal (ouch) and my doc gave me clindamycin and tylenol 3s. The infection was gone before the antibiotics. I have twenty four 150 mg capsules remaining. I need to do at least 30 plates w/ antibiotic. UCSD, I plan on doing it the same as you, except with peroxide since my spores have already germinated. What kind of concentration of clindamycin do you suggest?
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Anno
Experimenter



Registered: 06/17/99
Posts: 24,168
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Last seen: 18 days, 5 hours
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Re: Penicillin and streptomycin in agar [Re: YidakiMan]
#2760369 - 06/03/04 10:36 AM (20 years, 9 months ago) |
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Are you allergic to penicillin?
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YidakiMan
Stranger

Registered: 09/28/02
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Re: Penicillin and streptomycin in agar [Re: Anno]
#2760833 - 06/03/04 02:59 PM (20 years, 9 months ago) |
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I really do not have any allergies at all. Whenever I get a sinus infection, I usually get amoxicillin. This prescription was from my dentist.
I want to add the clindamycin to 600ml DFA that is cooling now. I'll add it at the same time I add the H2O2. How much would you think to add? I think I may only put in two capsules, for a total of 300mg.
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