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Mycosperiment
Stranger

Registered: 11/19/17
Posts: 198
Loc: USA
Last seen: 1 year, 10 days
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Re: polypropylene containers for use as petri dishes [Re: Spindlymass]
#25031562 - 03/01/18 11:58 AM (5 years, 11 months ago) |
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Quote:
Spindlymass said:
Quote:
Mycosperiment said: I cut the hinges on a couple of my containers and the lids don't easily sit level on the bases so a stack of them will likely fall over.
Do the lids get a little looser fitting once pressure cooked a few times?
True, they are a little off kilter but I can stack them... 7 high? Can't exactly remember. Sure, not as high as regular petris but works for me.
* edit, I remember now, I can stack them high enough to palm in my hand for pouring one after the other in the stack.
I haven't found the lids to get looser but they are fairly new to me and I've only PC'd them a couple times.
I just finished pressure cooking and filling some of these plates. I closed them and put them in a food storage container. A lot of the caps did pop open during PCing but didn't hurt them and more fit in the little food container at once.
I fit 20 closed plates in at once. I made 50 ml of media and got 18 of them filled with it. I'm loving these plates.
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Mycosperiment
Stranger

Registered: 11/19/17
Posts: 198
Loc: USA
Last seen: 1 year, 10 days
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Re: polypropylene containers for use as petri dishes [Re: Spindlymass]
#25031568 - 03/01/18 11:59 AM (5 years, 11 months ago) |
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Quote:
Spindlymass said: Remember to add vinegar to the PC water or the containers get a film and are even harder to see into.
Thanks for the tip. How much vinegar should I add?
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Spindlymass
wafer thin.



Registered: 09/25/17
Posts: 957
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Last seen: 14 days, 22 hours
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Re: polypropylene containers for use as petri dishes [Re: Mycosperiment]
#25031656 - 03/01/18 12:47 PM (5 years, 11 months ago) |
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It's an old canning trick (if you want to google).
I usually put in a 'glug' or two from the bottle... Maybe a couple tablespoons, 30ml? In my 23 quart presto.
-------------------- enough knowledge to get into trouble. Not nearly enough to get out again.
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Mycosperiment
Stranger

Registered: 11/19/17
Posts: 198
Loc: USA
Last seen: 1 year, 10 days
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Re: polypropylene containers for use as petri dishes [Re: Spindlymass]
#25031867 - 03/01/18 02:18 PM (5 years, 11 months ago) |
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Quote:
Spindlymass said: It's an old canning trick (if you want to google).
I usually put in a 'glug' or two from the bottle... Maybe a couple tablespoons, 30ml? In my 23 quart presto.
Thanks. That's close enough. Just wanted to know if it took a lot or just a little bit.
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sromes1

Registered: 07/21/08
Posts: 94
Loc: boston area
Last seen: 3 months, 13 days
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Re: polypropylene containers for use as petri dishes [Re: Mycosperiment]
#25038567 - 03/04/18 03:51 PM (5 years, 11 months ago) |
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good point. I use a small strip of aluminum between both tabs and twist to open seems to work good for the next size up
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Mycosperiment
Stranger

Registered: 11/19/17
Posts: 198
Loc: USA
Last seen: 1 year, 10 days
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Re: polypropylene containers for use as petri dishes [Re: sromes1]
#25038599 - 03/04/18 04:04 PM (5 years, 11 months ago) |
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Quote:
sromes1 said: good point. I use a small strip of aluminum between both tabs and twist to open seems to work good for the next size up
These ones became easier to open and close after a time through the pressure cooker but that might be easier than using fingernails to pry them open. This idea make me wonder if a thin strip of foil could be closed in between the base and lid to let them vent a little bit and prevent the caps from popping open or bulging out/sucking in from the pressure or vacuum. Probably not worth the effort but would allow more to fit in a small container to sterilize if they could be closed.
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Mycosperiment
Stranger

Registered: 11/19/17
Posts: 198
Loc: USA
Last seen: 1 year, 10 days
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Re: polypropylene containers for use as petri dishes [Re: 99.99]
#25058057 - 03/12/18 10:27 AM (5 years, 11 months ago) |
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99.99 said: Two options ive found https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F142485192370
And these from big lots that I'm currently using

I got the 1 oz containers and they look pretty good for the money. The lids are a little bit brittle and a couple were cracked when I got them. I didn't expect polypropylene to be brittle like that but they are marked PP on the bottoms and they did handle the pressure cooking temperatures.
The PVC cement does turn white after pressure cooking but I've used it many times on jar lids and other stuff. One advantage of adding the filter is that they can be filled and sterilized with the lid closed. Without any vents they either pop open or deform from the heat and pressure.
I probably won't use these as petri dishes because I have other ones I like better for that but plan to use some for miniature plant tissue culture containers. I just drilled a small hole in the lids of 10 of them and glued some synthetic craft felt filters on them using PVC cement. They won't have much space inside but should work ok for starting seeds or small pieces of plants in vitro.
Edited by Mycosperiment (03/12/18 10:42 AM)
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sromes1

Registered: 07/21/08
Posts: 94
Loc: boston area
Last seen: 3 months, 13 days
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Re: polypropylene containers for use as petri dishes [Re: Mycosperiment]
#25058092 - 03/12/18 10:46 AM (5 years, 11 months ago) |
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let us know how they work
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Spindlymass
wafer thin.



Registered: 09/25/17
Posts: 957
Loc:
Last seen: 14 days, 22 hours
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Re: polypropylene containers for use as petri dishes [Re: sromes1]
#25153710 - 04/20/18 03:40 PM (5 years, 9 months ago) |
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I thought I would update with my experience using my pp5 petris.
1. Using a translucent agar helps a lot with visibility of any growth. i.e., being able to look from underneath or shining light from underneath etc.
2. You can write and erase on them with permanent marker but remember to erase old plates before you PC them or they will stain permanently
3. Do not close them by pressing in the centre. The flexibility of the plastic creates a vacuum and I have had a number of petris suck contams in around the edges.* now I press around the perimeter to close.
*I haven't tested this with virgin petris, just a hypothesis from the contam growth patterns I found.
-------------------- enough knowledge to get into trouble. Not nearly enough to get out again.
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Mycosperiment
Stranger

Registered: 11/19/17
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Loc: USA
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Re: polypropylene containers for use as petri dishes [Re: Spindlymass]
#25153808 - 04/20/18 04:38 PM (5 years, 9 months ago) |
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Quote:
Spindlymass said: I thought I would update with my experience using my pp5 petris.
1. Using a translucent agar helps a lot with visibility of any growth. i.e., being able to look from underneath or shining light from underneath etc.
2. You can write and erase on them with permanent marker but remember to erase old plates before you PC them or they will stain permanently
3. Do not close them by pressing in the centre. The flexibility of the plastic creates a vacuum and I have had a number of petris suck contams in around the edges.* now I press around the perimeter to close.
*I haven't tested this with virgin petris, just a hypothesis from the contam growth patterns I found.
I also like the translucent agar for the same reason. I sometimes add some brewers yeast which doesn't all dissolve and makes it a little harder to see through. I don't know if it really makes any difference in the growth but many recipes I have seen use a little bit of it. The only time I use any food coloring in the agar is when I need to keep different media experiments separate but prefer nice clear media.
I did notice the permanent marker becoming more permanent (on other plastic containers) if pressure cooked. 91% rubbing alcohol removes it pretty easy BEFORE they are pressure cooked. 70% can be used if you add a bunch of salt to a little jar or tube of the weaker alcohol. The salt will soak up some of the water and sink to the bottom. The top layer of alcohol is then strong enough to remove the ink.
The PP containers are harder to see inside so not as nice as real plates but being reusable is very nice. The 1 ounce containers I got from ebay have worked pretty good so far. I glued on some filters and have done mini experiments with grain cultures. They are real nice for testing LC's or just to get a little bit of colonized grain which can be used for grain to grain transfers. I haven't tried them yet for agar work because the smaller containers are easier to work with but I'm sure they would work.
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Spindlymass
wafer thin.



Registered: 09/25/17
Posts: 957
Loc:
Last seen: 14 days, 22 hours
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Re: polypropylene containers for use as petri dishes [Re: Mycosperiment]
#25153853 - 04/20/18 05:11 PM (5 years, 9 months ago) |
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Yeah dude, I'm with you on all accounts. 
I've found that even a dry cloth or fingernail removes the permanent marker on my petris.
Cool trick with the salt and iso!
-------------------- enough knowledge to get into trouble. Not nearly enough to get out again.
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