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LitCloset
hypochondriac



Registered: 04/01/09
Posts: 632
Last seen: 4 years, 8 months
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? regarding reusing plastic petri and steri loops
#10833787 - 08/10/09 03:35 PM (14 years, 6 months ago) |
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so i have a ton of plastic petri dishes that i have used once. now i don't want to go out an drop another $100 to replace the huge amount of dishes i already have. the problem is these can not survive being autoclaved, trust me Ive tried it!
so last time i washed them real good. soaked em in bleach. cleaned em out with alcohol swabs. then prior to use i hit the lid and the bottom with a fine mist of 99% iso. i flipped them over on a clean service and allowed for them to mostly evaporate.
then i poured very hot agar (right out of the PC) in to the bottoms and the immediately placed on the lids.
1/3 of my dishes using PYDA were contaminated within 5 days. i only poured them, did not open them to inoculate etc.
so the hot agar is nice because that shocks anything in there (condensation is OK if you incubate them upside down). but all this is not good enough.
Short of buying a UV light what would y'all recommend?
i also have a large amount of BD blue steri loops. they are inoculation loops made of plastic that can not be autoclaved. i love using them in the box because no flame is needed. but i cant keep buying boxes of these things. ideas?
thanks
btw, if you have never heard of steri (sterile) loops, they are amazing. a back of 50 cost about $5. they come sterile, you put em in your box, take one out at a time and use it once then throw it away. its jsut so wasstefull if they cant be reused. but no fire, and no waiting for it to cool, they are made to pick up drop of 1ul 5ul 10ul etc. and they do not cut into agar as easily as metal ones.
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EdgeChaos
Still a stranger


Registered: 08/04/06
Posts: 2,071
Last seen: 6 years, 6 months
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Re: ? regarding reusing plastic petri and steri loops [Re: LitCloset]
#10834018 - 08/10/09 04:07 PM (14 years, 6 months ago) |
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I know this is frowned upon by some very respected members but...
I use a UVC lamp to sterilize my petri dishes there are still some that contaminate maybe 1 in 6 but it works well for me.
I think that complete sterility can be achieved with proper exposure and time.
Note: UVC is dangerous bla bla bla radiation, blindness, cancer and such. If you choose to use this technology make damn sure you don't let it get to any part of your body. An enclosed cabinet with external switch is the only smart way to successfully use UVC.
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LitCloset
hypochondriac



Registered: 04/01/09
Posts: 632
Last seen: 4 years, 8 months
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Re: ? regarding reusing plastic petri and steri loops [Re: EdgeChaos]
#10834093 - 08/10/09 04:17 PM (14 years, 6 months ago) |
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yeah,
all my brainstorming has led me to only one answer, UV light. i really don't have the money to buy it right now though.
what source did use use for the light you have? I'm not asking for the store you got it from. I'm wondering what it was being sold as/for. was it being sold to clean fish tanks or reptile cages? i don't think the lights at the pet store will quite do it, or maybe they will?
maybe i should just search for a very cheap UV light online that is made for this purpose, but that sounds more expensive than breaking up a tooth brush sanitizer. ideas?
I highly doubt the incadesent black light i own would do anything over any reasonable time frame. you know, the type for parties... if only
maybe if i made a hifgh voltage arc that would put out enough ozone and uv to do the job, but damn i dont know where my neon sign transformer is.
damn i need to get a job!!!!!!!
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LitCloset
hypochondriac



Registered: 04/01/09
Posts: 632
Last seen: 4 years, 8 months
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Re: ? regarding reusing plastic petri and steri loops [Re: LitCloset]
#10834118 - 08/10/09 04:21 PM (14 years, 6 months ago) |
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i have an electric steamer with multiple levels. has anyone ever tried this? sorry i know this topic has been discussed im hoping for new experiences.
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EdgeChaos
Still a stranger


Registered: 08/04/06
Posts: 2,071
Last seen: 6 years, 6 months
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Re: ? regarding reusing plastic petri and steri loops [Re: EdgeChaos]
#10834171 - 08/10/09 04:30 PM (14 years, 6 months ago) |
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Yeah I'm always afraid my lamp is going to catch shit on fire...
I found out that a "large orange home improvement store" carry's replacement UVC bulbs for an air purifier. These bulbs fit perfectly into a lamp called "the OTT light".
I always baby sit the lamp because I don't know enough about bulbs and electric devices to know if what I did is dangerous or not...
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LitCloset
hypochondriac



Registered: 04/01/09
Posts: 632
Last seen: 4 years, 8 months
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Re: ? regarding reusing plastic petri and steri loops [Re: EdgeChaos]
#10834378 - 08/10/09 04:53 PM (14 years, 6 months ago) |
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perfect i will look into it. if the cost is ok i will try testing the light out and ill post my review when its done.
thanks
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LitCloset
hypochondriac



Registered: 04/01/09
Posts: 632
Last seen: 4 years, 8 months
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Re: ? regarding reusing plastic petri and steri loops [Re: LitCloset]
#10835755 - 08/10/09 08:47 PM (14 years, 6 months ago) |
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ok i just used my 4 level electric steamer for the first time, i must say it is very cool!
but the petri dishes i put in there were dead in 5 minutes... the steri loops bent at the thin tip but otherwise they look usable. the bleach soak and the steaming probably has made them sterile. ill find out tomorrow when my agar has sat for long enough to harden (OK i just don't want to do it now...)
So steamer with steri loops maybe petri no Metal tools and the syringes i put in there, seem a OK!
ill be running the test on the syringes tomorrow.
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RogerRabbit
Bans for Pleasure



Registered: 03/26/03
Posts: 42,214
Loc: Seattle
Last seen: 11 months, 22 days
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Re: ? regarding reusing plastic petri and steri loops [Re: LitCloset]
#10835836 - 08/10/09 09:01 PM (14 years, 6 months ago) |
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Quote:
LitCloset said:
so last time i washed them real good. soaked em in bleach. cleaned em out with alcohol swabs. then prior to use i hit the lid and the bottom with a fine mist of 99% iso. i flipped them over on a clean service and allowed for them to mostly evaporate.
then i poured very hot agar (right out of the PC) in to the bottoms and the immediately placed on the lids.
1/3 of my dishes using PYDA were contaminated within 5 days.
I'm sure all of that cost more than the cost of new dishes. I get my three section dishes for about fifteen cents each by buying a box of 500. single section dishes are about a dime apiece.
Next time, let the agar cool until it's almost solidified before pouring. You shouldn't need heat protection for your hands. If you pour them hot, as they cool, the shrinking agar draws in contaminants.
Don't store petri dishes upside down either. That causes the moisture to fall out by gravity. RR
-------------------- Download Let's Grow Mushrooms semper in excretia sumus solim profundum variat "I've never had a failed experiment. I've only discovered 10,000 methods which do not work." Thomas Edison
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LitCloset
hypochondriac



Registered: 04/01/09
Posts: 632
Last seen: 4 years, 8 months
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Re: ? regarding reusing plastic petri and steri loops [Re: RogerRabbit]
#10836973 - 08/10/09 11:57 PM (14 years, 6 months ago) |
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hey RR! i actually just got done watching a few chapters of your video!
luckily i got the steamer for Christmas 2 years ago, i had never used it until now. i work in a lab on campus and so i and everyone else in the building uses tons of the loops and dishes everyday. i have access to all of them so its hard not to try for something. I'm talking boxes being thrown in the trash every day.
about storing the plates upside down, i have always been told to do this. but maybe its just not meant for mushroom growing? my medical micro teacher use to go into my incubator and flip them all upside down and knock off professional points. his reasoning was that there is usually condensation, so its better for it to fall off the agar and hit the lid then drop from the lid back into the agar making wet spots. i never really liked it so ill try it your way.
The reason i pour it so hot is to hopefully help kill anything in the plates that i didn't take care of, i didn't think of the problem you mentioned, so overall my method is counter productive. 
well i guess ill look into getting a nice, terribly scary and carcinogenic UVC lamp. i work with them all the time, i just don't have one in my home lab.
ill stop with the steri loops and use my nice metal inoculation loop instead. its not that bad having to bring it out of the box every time to flame it, and wait... the steri loops just do such a better job at holding water and gliding across the surface when you do isolation streaks or what not. damn they are wasteful.
Thanks RR, ill be buying the lamp if its not too expensive. otherwise ill just continue to throw these beautiful plates away, and pay for shipping. well i guess i could get some Pyrex ones as well
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Doc_T
Random Dude




Registered: 03/06/09
Posts: 42,395
Loc: Colorado
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Re: ? regarding reusing plastic petri and steri loops [Re: LitCloset]
#10837006 - 08/11/09 12:05 AM (14 years, 6 months ago) |
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The lamp is too expensive. And too dangerous. And too not usable.
-------------------- You make it all possible. Doesn't it feel good?
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Psuper
Psilocybin


Registered: 02/12/08
Posts: 2,874
Loc: PNW
Last seen: 3 years, 5 months
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Re: ? regarding reusing plastic petri and steri loops [Re: Doc_T]
#10837580 - 08/11/09 02:40 AM (14 years, 6 months ago) |
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Quote:
Doc_T said: The lamp is too expensive. And too dangerous. And too not usable.
Wrong.
-------------------- Clinical Management of High Dose Psilocybin Sessions: https://www.youtube.com/watch?v=FbHOTIqjZLk
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LitCloset
hypochondriac



Registered: 04/01/09
Posts: 632
Last seen: 4 years, 8 months
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Re: ? regarding reusing plastic petri and steri loops [Re: Psuper]
#10837640 - 08/11/09 03:02 AM (14 years, 6 months ago) |
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looking around on online auction sites and what not, the light scan be found for $10 or less. problem is at the moment thats too much for me...
anyone else hate being a poor student?
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newtogrowing
Mr. Green smiles



Registered: 07/29/09
Posts: 577
Last seen: 13 years, 4 months
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Re: ? regarding reusing plastic petri and steri loops [Re: LitCloset]
#10837697 - 08/11/09 03:18 AM (14 years, 6 months ago) |
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I'm no student but I still hate being poor ha ha
-------------------- [gradient:#FF0A0A,#03FF18]
Got to try to get results, got to improve that to have success, have to be successful to work on perfection
Pf Tek is the way to go, it's what I plan on sticking to, I fully support and suggest Pf Tek for everyone new or not, it's awesome it has results and is easy to follow. [gradient:#FF0A0A,#05FF05]FREAK OF THA FAMILY[/gradient]
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Doc_T
Random Dude




Registered: 03/06/09
Posts: 42,395
Loc: Colorado
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Re: ? regarding reusing plastic petri and steri loops [Re: Psuper]
#10837934 - 08/11/09 05:56 AM (14 years, 6 months ago) |
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Quote:
Psuper said:
Quote:
Doc_T said: The lamp is too expensive. And too dangerous. And too not usable.
Wrong.
You can find a UV lamp that will sterilize plastic dishes, but is safe to work with? I'm willing to be enlightened, please post a link or details.
(It's probably changed a lot since I looked, won't be hard to impress me.)
-------------------- You make it all possible. Doesn't it feel good?
Edited by Doc_T (08/11/09 06:06 AM)
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EdgeChaos
Still a stranger


Registered: 08/04/06
Posts: 2,071
Last seen: 6 years, 6 months
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Re: ? regarding reusing plastic petri and steri loops [Re: Doc_T]
#10838077 - 08/11/09 07:30 AM (14 years, 6 months ago) |
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Too expensive maybe. dangerous yes. not usable no way.
If I remember correctly my lamp cost me 50 for the bulb and the ballast. It has been worth it so far.
UVC light can cause all kinds of bad things. Something being dangerous never stopped me from using it, I always found a way to make it safe. put the lamp in a closed space and turn it on from the outside. simple, safe, no cancer.
I just put the disposable petri dishes in the bag they came in and twist tie it off. put it in the cabinet, position the lamp, close the cabinet, turn the light on, wait 30min or so and take them out.
The only thing I am worried about is whether or not my jerry rigged lamp is a fire hazard.
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RogerRabbit
Bans for Pleasure



Registered: 03/26/03
Posts: 42,214
Loc: Seattle
Last seen: 11 months, 22 days
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Re: ? regarding reusing plastic petri and steri loops [Re: LitCloset]
#10838419 - 08/11/09 09:13 AM (14 years, 6 months ago) |
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Quote:
LitCloset said: about storing the plates upside down, i have always been told to do this. but maybe its just not meant for mushroom growing? my medical micro teacher use to go into my incubator and flip them all upside down and knock off professional points. his reasoning was that there is usually condensation, so its better for it to fall off the agar and hit the lid then drop from the lid back into the agar making wet spots. i never really liked it so ill try it your way.
Unfortunately, your teacher was inexperienced. Condensation forms on the warm side of a surface whenever there's a temperature differential. Mycelium itself produces heat, thus condensation will form. That's why we keep colonizing petri dishes in a vertical stack. This eliminates the temperature differential and stops condensation from forming in the first place. Don't store petri dishes upside down. RR
-------------------- Download Let's Grow Mushrooms semper in excretia sumus solim profundum variat "I've never had a failed experiment. I've only discovered 10,000 methods which do not work." Thomas Edison
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Psuper
Psilocybin


Registered: 02/12/08
Posts: 2,874
Loc: PNW
Last seen: 3 years, 5 months
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Re: ? regarding reusing plastic petri and steri loops [Re: Doc_T]
#10839443 - 08/11/09 12:59 PM (14 years, 6 months ago) |
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Quote:
Doc_T said:
Quote:
Psuper said:
Quote:
Doc_T said: The lamp is too expensive. And too dangerous. And too not usable.
Wrong.
You can find a UV lamp that will sterilize plastic dishes, but is safe to work with?
nah, you're right....and no i probably couldn't find something really safe for cheap, lol, i would build something. and i sure wouldn't recommend one. I've just seen them used too often in a profesional setting, you're obviously right to not recommend them, there dangerous, i was just trying to argue. ~P~
-------------------- Clinical Management of High Dose Psilocybin Sessions: https://www.youtube.com/watch?v=FbHOTIqjZLk
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