When you pressure cook a liquid culture jar (with no tyvek vent) a strong vacuum will form within the jar. That vacuum is strong enough to suck a 10mL spore syringe dry within less than a second. A vacuum can also suck in contaminants when you pierce the injection port. Vacuums are bad and need to be vented.
After a liquid culture is colonized, you will need to remove the mycelia rich water to inoculate jars. When you use a syringe to remove 10mL of liquid from a sealed container, you need to put back in 10mL of air or a vacuum will form. Vacuums are bad and need to be vented.
The airport syringe allows you to introduce highly filtered air. It allows you to vent the vacuum with no risk of contamination.
Polyfill can be acquired at any “Mart,” fabric or sewing store. Polyfill is a fluffy synthetic material used to stuff pillows and toys. It is also called polyester batting. You can also acquire Polyfill from aquarium stores, where it is called synthetic filter material, polyester filter material or angel hair filter material. Polyfill from the aquarium shop will cost more than polyfill from the fabric store, but it will be the same material.
- 10mL Luer lock syringe with 18-20 Ga needle
- Handful of polyfill
If you absolutely can’t find Polyfill, you can use medical grade non-absorbent cotton (unbleached). DO NOT USE COTTON BALLS FROM THE DRUG STORE. If you use cotton, you have to be careful not to let it get wet when pressure cooking. If it does get wet, you have to let it dry out and then re-sterilize before use. Cotton airport syringes should always be wrapped tightly in aluminum foil before being PCed. Cotton is drastically inferior to polyfill for airport syringes.
Start by removing the plunger and needle from your 10mL syringe. Grab a handful of Polyfill and twist it into a smallish cylinder with a point.
Twisted Polyfill, ready for syringe insertion.
Force the Polyfill into the syringe and, while twisting continuously, force enough material into the syringe to fill it about 90% full.
Without letting any polyfill come out of the syringe, untwist it so that it expands inside the syringe body. Cut the polyfill with a sharp pair of scissors. Using the syringe plunger, force the filler material down into the syringe ½ inch or so. You don’t want fibers sticking out everywhere. Twist the needle on and it will look like this:
Completed airport syringe.
Making two or three of these is a good idea, if you have the syringes to spare. Hint: you can get syringes REAL cheap (in bulk) on eBay...
Before use, the airport needs to be sterilized. Wrap it up in an aluminum foil envelope and put it in the PC at 15psi for 30 minutes (or longer). You can cook tools like this whenever you cook jars. You don’t have to sterilize an airport syringe between every use (it doesn’t hurt), but you should flame the syringe red hot between each jar/use.
Only insert the airport syringe a short distance into the injection port when using it. You only want the part of the syringe that got red hot during flaming to go past the silicone injection port. Let a red hot syringe needle cool for at least 5 seconds before injecting a port. A red hot needle will damage silicone.
Below is a silicone injector port lid and airport syringe in action. As water is drawn into the 60mL syringe, sterile filtered air is drawn through the airport syringe. The pint jar of tap water was run through the PC to sterilize. Sterile water was removed from the pint for a number of weeks without becoming contaminated, using the airport syringe and silicone injection ports.
Airport syringe and injector ports in action.
Silicone injection ports and airport syringes allow the home mycologist to work with a much lower risk of contamination.
BB does airports
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Posted 20 August 2006 - 09:44 AM