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Topics - psilly

#1
PF - Tek / Petri Colonization?
October 02, 2004, 11:53:28 AM
I sterilized 22 glass petri dishes, along with a jarful of standard RBF/verm mix and a jarful of pure vermiculite.  All contents were placed in a glove box and allowed to cool.  Then I placed chunks of the RBF/verm mix into each jar, inoculated with 3 drops spore solution, sprinkled with dry vermiculite, and covered with glass petri lids.

I removed the petri dishes from my glovebox, placed them on a sterilized plastic tray, and put the tray in a black plastic trash bag, which I then set on top of a heating pad with adjustable temp settings.  After four days at least five of the dishes have signs of nice, fluffy, mycelial growth.

Once the dishes are fully colonized, which I'm guessing will take between 1 week to 10 days from inoculation, the idea is to see if I can use 1/2 the contents of each dish to inoculate a standard PF jar setup.  I'm expecting contam rates to be higher due to the transfer process, but if I can inoculate 44 jars using 5cc spore solution, I can afford to lose a few. ;)

I'll keep you informed from time to time, worst case scenario I've wasted half a syringe and a little bit of effort.
#2
Cultivation / Cheap glove box
August 26, 2004, 04:24:30 AM
Materials (less than $40 bucks at your local Mega-Mart):

2 plastic lettuce crispers with airtight lids
1 clear plastic storage bin
Plastic Weld
Window caulk

1.  Cut the bottoms out of the lettuce crispers leaving maybe 2" from the rim.
2.  Place the rims on the bottom of the storage bin, right where you want the arm-holes, and trace.
3.  Cut along the lines just traced to create 2 holes (same size as the rims).
4.  Using the plastic weld, join the cut surfaces of the rims to the cut surfaces of the storage bin.  Try to get as tight a seal with the epoxy as possible.
5.  Allow plastic weld to completely dry, following the instructions on the tube.
6.  If you're unsure about a tight seal, you can caulk the OUTSIDE of the glove box.  Dried caulk is somewhat porous, and might make an excellent medium for unwanted microbial critters, so caulking on the inside of the glovebox is not recommended.

NOTES:

--The nice thing about plastic is that it's easy to clean.  Before using my glove-box, I sterilize with 10% bleach solution, allow it to dry, and then use Lysol.

--Before working in my glove-box, I wash my arms and forearms with antibacterial soap, apply a topical disinfectant, remove the crisper lids to allow access, and don surgical gloves before inserting my hands.  An "air sheild" can also be temporarily installed by taping a sheet of clean plastic above the arm-holes, allowing the sheeting to hang freely over the arm-holes while you work (you reach under the sheet to gain access to the arm-holes); this further protects your workspace from airborn particles.  When finished, you can replace the crisper lids to get an airtight seal.

--Arm-hole placement is on the bottom of the storage bin because most bins are taller than they are wide.  This means that the box will sit on its side when in use, giving you a larger work area than you would get if the box was sitting upright.

--The storage bin's lid is (most likely) NOT airtight.  However, permanently sealing this lid would make the glovebox extremely difficult to clean between uses.  A simple work-around is to stuff cotton balls or paper towels into the "groove" where the lid fits on, and then temporarily seal with duck tape after sterilizing the inside workspace.  When you're through with the glovebox, this tape can be cut away to allow for thorough cleaning before the next use.

--You should be able to get an airtight seal around the arm-holes with the lids that go on the lettuce crispers.  This allows you to completely seal off the glovebox when you're not actively working inside.  If in doubt, you might want to water-test the crisper lids before applying any epoxy.

--The glovebox is exposed when you're working.  It's only actually airtight before and after you gain access, when the arm-holes are sealed off.  However, the goal here is to eliminate as many contams from the work environment as possible without a huge monetary investment.  In my opinion, the trade-off between less airtight and easier to thoroughly sterilize before use is a fair one.  However, it wouldn't be too difficult to seal gloves over the armholes if you're concerned about this.