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bodhisatta 
Smurf real estate agent


Registered: 04/30/13
Posts: 61,889
Loc: Milky way
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Quote:
Sandstone said: Wow never imagined you could leave an active petri unwrapped..cool. So all of the sterile, aseptic, still air or even flowhood jazz is compressed into about two steps and then you can just leave it without tape, glass lids fitting like shit and nothing happens 
You shouldn't store them unwrapped. Just because one person had success isn't what I would go by.
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Sandstone
Cosmonaut

Registered: 09/23/20
Posts: 88
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Yeah makes sense I'm still not sure tho..one pours in the smaller dia piece of a petri dish and then covers that with a larger dia lid right?
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bodhisatta 
Smurf real estate agent


Registered: 04/30/13
Posts: 61,889
Loc: Milky way
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Yea and they're not air tight on purpose
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Inthepit
Aum Mani Padme Hum



Registered: 08/20/19
Posts: 1,742
Loc: Puerto Rico
Last seen: 12 days, 22 hours
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There's Cling Wrap, Grafting Tape (gardeners), and Parafilm.
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mind.at.large
Myconerd


Registered: 12/13/16
Posts: 1,218
Loc: Floating in liquid gardens
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Re: Glass petris [Re: Inthepit]
#27019486 - 11/03/20 01:38 PM (3 years, 2 months ago) |
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I usually just treat them like no pours. As in I make agar, pour into plates then put them in the PC as is and sterilize as usual. I’ve never really had a problem with them doing it this way.
-------------------- Mind's Easy Bag 2 Bag Grain Transfers Endless Sub Tek ...the doll's trying to kill me and the toaster's been laughing at me...
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Inthepit
Aum Mani Padme Hum



Registered: 08/20/19
Posts: 1,742
Loc: Puerto Rico
Last seen: 12 days, 22 hours
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Quote:
mind.at.large said: I usually just treat them like no pours. As in I make agar, pour into plates then put them in the PC as is and sterilize as usual. I’ve never really had a problem with them doing it this way.
Not to hijack this thread, but how do you avoid HORRIBLE condensation.
I'd like to no-pour or pre-pour and tried several teks, all were a sloppy mess. From what i've read it's not worth it. But perhaps this is entering a kind of religious war, wait where's my hat.  Francis Bacon 1950 Study after Velázquez
Edited by Inthepit (11/03/20 02:54 PM)
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mind.at.large
Myconerd


Registered: 12/13/16
Posts: 1,218
Loc: Floating in liquid gardens
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Re: Glass petris [Re: Inthepit]
#27019884 - 11/03/20 05:14 PM (3 years, 2 months ago) |
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To be honest the condensation is not that bad. They usually clear up rather quick. The glass ones I have are pretty small. I got these ones for free, so I might as well use them but I don’t prefer them. I probably wouldn’t buy any more. I like holy grails or just regular plastic petris.
But condensation is not really a worry of mine. It’s annoying, but as long as I’m clean, some condensations fine.
That being said, cleaning up a wild tissue culture on a plate with a ton of moisture spreading bacteria around is a bitch...
I always like to have some plates waiting that have been sitting around for a week or so. By that time most if not all the condensation is gone
-------------------- Mind's Easy Bag 2 Bag Grain Transfers Endless Sub Tek ...the doll's trying to kill me and the toaster's been laughing at me...
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Sandstone
Cosmonaut

Registered: 09/23/20
Posts: 88
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Quote:
bodhisatta said: Yea and they're not air tight on purpose
I believe they are, I just dont know why. Gas exchange? Preventing heat distortion/cracking and provide enough give/expansion/contraction? I can go google it but as we're at it, I might as well ask  Cheers
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polaritymind
relaxed attention


Registered: 10/10/16
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Loc: Germany
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I do no pour with old 1/2 pint or what was it, the old pf tek style jars and dont have problems with too much condensation. The times I did though, it was often because I cooled them too fast so no releasing pressure early or any of that funny business, leave them to cool in the PC overnight. But then again maybe its my Agar recipe thats not that wet, what do I know.
Also as far as gas exchange goes I find its not that important, the little air in the jar is enough for colonizing half the plate and after a while it stalls, which I had the idea could be a type of long term storage method or something. I am talking about no filter type lids screwed on tight in my case.
-------------------- "to affirm life is to also affirm death" -Albert hofmann
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Sandstone
Cosmonaut

Registered: 09/23/20
Posts: 88
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So, if I opt for no pour oven sterilization. Won't I burn the sugars and make a mess out of agar, staying at 450F for TWO hours?
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Sandstone
Cosmonaut

Registered: 09/23/20
Posts: 88
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Quote:
polaritymind said: I do no pour with old 1/2 pint or what was it, the old pf tek style jars and dont have problems with too much condensation. The times I did though, it was often because I cooled them too fast so no releasing pressure early or any of that funny business, leave them to cool in the PC overnight. But then again maybe its my Agar recipe thats not that wet, what do I know.
Also as far as gas exchange goes I find its not that important, the little air in the jar is enough for colonizing half the plate and after a while it stalls, which I had the idea could be a type of long term storage method or something. I am talking about no filter type lids screwed on tight in my case.
That's what I was thinking..that condensation only appears if there's a great temperature difference, too fast. Also GE is not that important if one takes for granted that no condensation happens. But does the condensation also evaporate if there's no gas exchange? Does the agar absorb the condensed water or does it actually evaporate out the petris? Due to obvious lack of actual experience working with agar, I'm only working with theory, trying to get familiar with everything there is to fuck up about agar, BEFORE I actually go do itXD

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Sandstone
Cosmonaut

Registered: 09/23/20
Posts: 88
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Re: Glass petris [Re: Inthepit]
#27020596 - 11/04/20 01:18 AM (3 years, 2 months ago) |
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Quote:
Inthepit said: There's Cling Wrap, Grafting Tape (gardeners), and Parafilm.
Which one works best? Is the parafilm the only one that allows evaporation and gas exchange? It's certainly the most pricey that's for sure
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Sandstone
Cosmonaut

Registered: 09/23/20
Posts: 88
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I was thinking of doing it in the oven purely because I can't fit much in this PC at the moment..which is kind of lame but am somehow managing it..still learning so doesn't bother me to get creative or something..
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Sandstone
Cosmonaut

Registered: 09/23/20
Posts: 88
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Re: Glass petris [Re: Inthepit]
#27020602 - 11/04/20 01:21 AM (3 years, 2 months ago) |
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Quote:
Inthepit said:
Quote:
mind.at.large said: I usually just treat them like no pours. As in I make agar, pour into plates then put them in the PC as is and sterilize as usual. I’ve never really had a problem with them doing it this way.
Not to hijack this thread, but how do you avoid HORRIBLE condensation.
I'd like to no-pour or pre-pour and tried several teks, all were a sloppy mess. From what i've read it's not worth it. But perhaps this is entering a kind of religious war, wait where's my hat.  Francis Bacon 1950 Study after Velázquez
What about ovens? Would the heat and time of exposure screw up the agar?
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SingularFusion


Registered: 10/31/18
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Last seen: 8 hours, 1 minute
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Quote:
Sandstone said:
Quote:
Inthepit said: There's Cling Wrap, Grafting Tape (gardeners), and Parafilm.
Which one works best?
cling always served me well
you take a fresh roll and divide it into sections of a width you like for wrapping and saw through with a sharp knife. Make a bunch of rolls at once, store them in a fresh ziploc. Dirt cheap and easy
you take one roll to the SAB where it will live, when you sit down to do work you just throw the first half foot or so off the roll, the rest of the roll is good to go
parafilm costs a fortune here where I am and yes cling breathes also allegedly
think I learned all that from bod's agar thread IIRC, don't wanna go back and check right now eh but it has always worked nicely for me
-------------------- 🅃 🄴 🄰 🄼 🄲 🄻 🄸 🄽 🄶 🅆 🅁 🄰 🄿
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MushRock
Stranger



Registered: 10/20/20
Posts: 40
Loc: The netherlands, Utrecht
Last seen: 3 years, 1 month
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That sounds like a great idea. Will try it for sure. Somehow I don't feel confident in using petri dish without tape, on long terms. How do yo apply the cling wrap on petri? Same as para-film tape, or do you wrap the hole dish so its covered in cling wrap.
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bodhisatta 
Smurf real estate agent


Registered: 04/30/13
Posts: 61,889
Loc: Milky way
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Re: Glass petris [Re: MushRock]
#27021234 - 11/04/20 11:12 AM (3 years, 2 months ago) |
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Just read a agar tek. Then ask questions. There's videos even how to do it.
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funky123
Pilzfreund


Registered: 08/27/17
Posts: 257
Loc: Austria
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Quote:
Sandstone said: Ok, so after receiving another(first ones arrived shattered, no packaging whatsoever) shipment of 100mm petris, I sanitized them, wrapped them individually in foil, made 2 packs of 4 petris. ...
> Can I just handle that packs up until the point I actually unwrap the whole deal inside the SAB? > Or is the sterility compromised as soon as I take them out of the oven? > Or will they stay sterile and can actually use them whenever I cook up some agar...? > Maybe unwrap the first layer of the pack right before placing them in a SAB, leave the most of the gained contaminants outside?
When you buy lab grade sterilized plastic dishes you also don't throw away the dishes you didn't use. You just reclose the wrapping and put them somewhere. So, no, you don't have to use them immediately - but I wouldn't wait too long. Why would you - I mean you just heat-sterilize before you need them.
> Also, is it possible that some petris actually cracked inside the oven?
Of course, that is possible. If they are low quality with invisible tensions in the glass. Otherwise it's unlikely.
Quote:
Sandstone said: Ok, just found out that I probably maintained that temp one whole hour short..should have stayed above 340F for like 120min? How high can I overshoot temperature wise and still keep my petris whole?
Bod recommends in his Agar Tek to boil the Agar for 20 minutes at 15psi (about 125°C). As you pour the Agar into the dishes - that's what your weakest link in the sterilization chain is. So, 60 minutes at 170°C should be alright. I set my oven to 250°C - because I can.
Quote:
bodhisatta said: If you don't end up hating glass dishes more power to you. I used oven sterilization. But then started buying plastic dishes because they're way superior.
I'm also pretty happy with glass dishes for mainly three reasons:
- I don't like to produce more waste than necessary.
- I don't have to order them every time.
- On a rubber surface they stay put without having to hold them. Which makes cutting wedges out easier (left hand holds lid, right hand cuts)
Quote:
Sandstone said: Although on the other hand, the amount of tinfoil, oven time, sanitizing, and all that jazz on the other hand..I don't know man 
I just use one sheet of tin foil to sandwich the dishes with it on both sides, closing the sides by folding the edges together. You could even use a pot as a container. Would take longer for them to cool down, though. No need to individually wrap the dishes.
Quote:
MushRock said: I am trying out to use pour technique, but my 1st attempts was while using little too hot agar mixture. So next plates also got condense.
I don't worry about condensation. I just put a flat-bottomed cup with hot water on the top lid for a few minutes and the condensation is gone. The condensation water usually vanishes after doing that once or twice because it gets reabsorbed into the agar or by the mycelium. Or maybe due to gas exchange through the parafilm.
Edited by funky123 (11/04/20 01:41 PM)
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Sandstone
Cosmonaut

Registered: 09/23/20
Posts: 88
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Re: Glass petris [Re: funky123] 1
#27021529 - 11/04/20 01:47 PM (3 years, 2 months ago) |
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That is an awesome post funky, thanks alot

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