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 shymanta
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Posts: 907
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 Is it necessary to dry agar plates? 
#5088102 - 12/21/05 02:05 AM (15 years, 11 months ago) |
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Is it necessary to dry agar plates?
I found a page that describes a method of drying the plates. http://www.science-projects.com/PlateDrying.htm
I couldn't find any info on this on the Shroomery. I would love some feedback on this. Thanks!
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 Anno
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Re: Is it necessary to dry agar plates? [Re: shymanta]
#5088253 - 12/21/05 02:44 AM (15 years, 11 months ago) |
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What they say can be true, namely that much condensation can accumulate in the agar plates after pouring.
This condensation gets absorbed back by the agar, and some also evaporates slowly of the course of several weeks in closed plates.
If you need them immediately, I would suggest to use the technique described here
www.fungifun.org/agar
over drying.
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armedia
Dikaryon
Registered: 11/03/01
Posts: 169
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Re: Is it necessary to dry agar plates? [Re: Anno]
#5088578 - 12/21/05 07:47 AM (15 years, 11 months ago) |
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IME, water is most likely to accumulate when plates are stored for long periods and/or rapidly shifted from warm to cold environments, and vice versa.
Rush Wayne suggests leaving newly poured (peroxide-containing) plates out for a few days in stacks of two or three, covered with a layer of fresh paper towels to firm them up before storing or using. If you had a large flowhood, you could do this with peroxide free plates too.
Another trick is to use a greater percentage of agar, 22-25g/l in your recipe. And Anno's trick helps too. It's usually the plates at the top of stacks that end up with the most condensation, since they cool fastest.
The method described here seems likely to lead to contamination, unless you have a sterile environment to perform it in.
- A
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RogerRabbit
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Re: Is it necessary to dry agar plates? [Re: armedia]
#5089279 - 12/21/05 12:30 PM (15 years, 11 months ago) |
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The key is waiting until the agar is barely still warm enough to pour. If you pour very hot agar, you will have condensation problems. Let the agar cool until you can hold the bottle in your bare hands without protection from the heat. Pour the dishes, then slip them back into the sleeve they came from. Leave them in a stack of 20. Only the top dish or two and the bottom dish will have any condensation that way. As anno said, most of the condensation is absorbed back into the agar anyway. The advice given at http://www.science-projects.com/PlateDrying.htm is the most horrible advice I've ever seen regarding agar. Do NOT put the freshly poured plates in the refrigerator. That will CAUSE condensation. Also NEVER remove the lids unless in a glove box or in front of a flow hood, and never have the lids off more than a few seconds to make your transfer. Paper towels may be 'clean' but they're not sterile, and will do nothing to stop contaminant spores in the air from landing on your plates. Trying to use a paper towel as a filter is like trying to catch a mosquito with a fishing net.
RR
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durban_poison
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Re: Is it necessary to dry agar plates? [Re: shymanta]
#5095383 - 12/22/05 09:37 PM (15 years, 11 months ago) |
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i just dont wrap them in parafilm for 14-24 hrs after pouring. i just leave them stacked in front of the flow hood. they are then condensation free and are ready to go.
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Hotnuts
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Re: Is it necessary to dry agar plates? [Re: durban_poison]
#5095969 - 12/23/05 12:02 AM (15 years, 11 months ago) |
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Adding peroxide to agar is worthless. I've seen Rush's open air inoculation tek for petri's and it's a crock. Not that i'm knocking Dr. Wayne in any way now. But, that's a worthless and unreliable technique. As Rodger mentioned, if you have the means to pour your agar while it's just warm that's the best way to avoid condensation in plates. If not, pour while the agar's very hot, put the lid on and immediately wrap the dish with plastic wrap. Right in the open air. If you lay the dish on the wrap with the lid resting to the side, you can pour while the agar's very hot, then put on the lid and wrap immediately for cooling. It will be level when cooled if you have the dish on top of the wrap. Once cool and the agar's hard, motivate it in to your gloove box or in front of sterile air flow, taking off the wrap and lid and allow the condensation to evaporate before inoculation. Inoculate and wrap with parafilm. Sometimes in small gloove boxes it can be a pain in the butt to pour agar. A hot pour cleans your dish of most contaminates as well...
Edited by hotnutz (12/23/05 12:30 AM)
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Anno
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Re: Is it necessary to dry agar plates? [Re: Hotnuts]
#5096938 - 12/23/05 07:21 AM (15 years, 11 months ago) |
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Quote:
Adding peroxide to agar is worthless. I've seen Rush's open air inoculation tek for petri's and it's a crock
I have used peroxide agar for several years very successfully before I had a flow hood. IMO it works very well.
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armedia
Dikaryon
Registered: 11/03/01
Posts: 169
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Re: Is it necessary to dry agar plates? [Re: Hotnuts]
#5097063 - 12/23/05 09:11 AM (15 years, 11 months ago) |
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No offense, but it's somewhat ridiculous to claim you aren't "knocking" Rush Wayne while simultaneously calling his central method "worthless" and "worthless and unreliable". This method is quite reliable, and has been used by many cultivators to great success, both here and elsewhere. Perhaps you should give it another try before you dismiss it so thoroughly, or defer to the many who have.
6-8mL 3% H2O2 added to 1l of agar, or 10mL per QT grain jar after sterilization & cooling will protect cultures from contamination and allow them to be handled openly without need of glovebox or flowhood. I do cloning and transfers in the open in a typically dirty kitchen, and my contamination rate is less than 1%. And I have yet to find a species of fungus that won't grow in the presence of peroxide.
- A
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Hotnuts
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Re: Is it necessary to dry agar plates? [Re: armedia]
#5097219 - 12/23/05 10:50 AM (15 years, 11 months ago) |
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I shouldn't say it's a crock. That wasn't very nice was it? I had a bad night, so forgive me for that statement if you will... 
Now here you guys are claiming it to be successful, while others have had many problems with that technique. Myself included. Especially with 3%'s use in grains. I guess if it works out for you, then you can't complain about it huh? I certainly wouldn't recommend it to anyone though.
Well, Happy Holidays guys and gals...
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X24
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Re: Is it necessary to dry agar plates? [Re: Hotnuts]
#5098576 - 12/23/05 06:21 PM (15 years, 11 months ago) |
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i actually paid for that tek and i give the guy props. im using it right now as a side project and its goin very well. if i thought it was worthless i would distribute the literature openly, but i dont. dont dis the dude, hes making a living at it. we only dream of a legal living. im envious of him for that.
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shymanta
Mad Scientist
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Re: Is it necessary to dry agar plates? [Re: X24]
#5100871 - 12/24/05 08:02 AM (15 years, 11 months ago) |
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I poured 20 or so plates (nicely cooled) the other day and just stacked them. I was going to follow what was on fungifun.com and put a cup of hot water on top of the stack, but condensation was not as big a problem as I though it might be. The Glad Clingwrap works great! A $2.50 box of that stuff makes 7 rolls of parafilm tape.
I poured 6 without H2O2 to inoculate with spores and the rest with H2O2 for mycelium. 2 of the 6 have contaminated. None of the others have yet.
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agar
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Re: Is it necessary to dry agar plates? [Re: Anno]
#5101829 - 12/24/05 02:41 PM (15 years, 11 months ago) |
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Quote:
Anno said:
Quote:
Adding peroxide to agar is worthless. I've seen Rush's open air inoculation tek for petri's and it's a crock
I have used peroxide agar for several years very successfully before I had a flow hood. IMO it works very well.
Listen to THE MAN 
If I knew one tenth of what he does, I would be a better cultivator, than I am.
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Demonsmoke
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Re: Is it necessary to dry agar plates? [Re: agar]
#21909109 - 07/07/15 12:29 PM (6 years, 5 months ago) |
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So another condensation question here. I poured 20 dishes after my bottle cooled enough for me to handle it and then I stacked them in the plastic sleeve and went to sleep. Passed out around 3am and checked them at around 12pm. There is light condensation on most of the lids. However, after opening the top petri to inspect closer I notice that the agar is not wet as the lids are.
Would it be wise to let them air with the lids off or wipe the lids down? Would it be better to assume the agar will reabsorb the condensation instead?
Small details are actually the biggest sometimes!
Edited by Demonsmoke (07/07/15 12:30 PM)
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matsc
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Re: Is it necessary to dry agar plates? [Re: Demonsmoke]
#21909270 - 07/07/15 01:10 PM (6 years, 5 months ago) |
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A little condensation on the lids isn't really a big deal. Heavy condensation can be trouble, but a bit of fog on the lid is just a fact of life (and even a dry lid will usually get some condensation on it if placed in a warm location for incubation, especially if parafilmed).
The agar itself will usually look "dry". Its rather like a stiff jello. As long as its not a shrunken little film of crust on the bottom of the plate, you're probably in good shape. If you really feel the need to let the condensation dry a bit, put your plates out (keep the lids on) and just leave them alone in a clean, cool place for a few hours.
But again, its really not a big deal. Wiping the lids is a HUGE contamination risk for such a tiny issue.
Edit: (wow, bumping a 9 year old post. Oh well. The shroomery search function really does need some better sort options doesnt it)
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Edited by matsc (07/07/15 01:13 PM)
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Demonsmoke
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Re: Is it necessary to dry agar plates? [Re: matsc]
#21910038 - 07/07/15 04:47 PM (6 years, 5 months ago) |
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Quote:
matsc said:
...plates out (keep the lids on) and just leave them alone in a clean, cool place for a few hours.
But again, its really not a big deal. Wiping the lids is a HUGE contamination risk for such a tiny issue.
Edit: (wow, bumping a 9 year old post. Oh well. The shroomery search function really does need some better sort options doesnt it)
Well, I figured bumping an older post would be better than creating a new one that covers the same topic. Using the search function allows you to pick up where others left off. I think the fact that 9 year old posts are being sought out and bumped back to life shows just how reliable and time tested a lot of the info is.
Thanks for the reassuring advice.
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Demonsmoke
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Re: Is it necessary to dry agar plates? [Re: Demonsmoke]
#21910387 - 07/07/15 06:14 PM (6 years, 5 months ago) |
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Also, should I wait for the condensation to evaporate/reabsorb to go forward with adding spores to the agar?
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Toadstool5
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Re: Is it necessary to dry agar plates? [Re: Demonsmoke]
#21910417 - 07/07/15 06:23 PM (6 years, 5 months ago) |
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Its more the fact that this is advanced myco and they prefer to keep it in the context of discussions rather than support-type FAQ.
Second rule of advanced myco club is
Quote:
This forum is for the discussion of advanced techniques and experimental procedures. This forum is NOT a support forum, for problems with your grows. Any posts regarding how to use a pressure cooker, your PF Cakes, a species which has been cultivated ad nauseam, grain ratios, contaminated grows, how to prepare dung, or anything else which has been covered in the forum, etc... will be moved immediately upon review - so please, do not waste the resources, time, or bandwidth of the shroomery.
The main problem with condensation is the loss of visibility, you should be good to add the spores.
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matsc
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Re: Is it necessary to dry agar plates? [Re: Demonsmoke]
#21910441 - 07/07/15 06:26 PM (6 years, 5 months ago) |
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It wont really hurt anything. If it drips onto the plate it might spread them around a bit, but that's about the worst of it. Only real major concern with condensation is if its at the very edge and drips down the edge, which can leave a thin highway for contamination to get in.
(Unless you're culturing yeast or bacteria for isolation, that is. Drips make it a pain in the ass to pick single colonies in those cases, but thats not the issue here)
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Toadstool5
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Re: Is it necessary to dry agar plates? [Re: matsc]
#21910533 - 07/07/15 06:45 PM (6 years, 5 months ago) |
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Quote:
Only real major concern with condensation is if its at the very edge and drips down the edge, which can leave a thin highway for contamination to get in.
Another good reason to use parafilm other than preventing the culture from drying out.
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If you do not know where the mushroom products you are consuming are grown, think twice before eating them.
- Paul Stamets
AMU Teks Stro's Write Ups
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Demonsmoke
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Re: Is it necessary to dry agar plates? [Re: Toadstool5]
#21911854 - 07/07/15 10:59 PM (6 years, 5 months ago) |
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Quote:
Toadstool5 said:
Its more the fact that this is advanced myco and they prefer to keep it in the context of discussions rather than support-type FAQ.
Point taken and thanks for the info fellas.
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