|
Some of these posts are very old and might contain outdated information. You may wish to search for newer posts instead.
|
prajnaparamita
Stranger

Registered: 07/22/06
Posts: 68
Last seen: 15 years, 9 months
|
needle sterilization question
#5921973 - 08/01/06 01:53 PM (17 years, 5 months ago) |
|
|
I'm a newbie so forgive me if this suggestion introduces some kind of obvious problem, but I had an idea for increase sterility of the needle during inoculation, particularly in an environment with many airborne contaminants.
Couldn't you take some cotton, in any kind of stackable form (swabs might not work), and do the following:
1. Soak one in alcohol, wring out excess. 2. Leave the other dry. 3. Cut out a small piece of plastic, such as from a sandwich baggie. 4. Layer the alcohol-soaked cotton on top, the plastic between, and the dry on the bottom. 5. Sterilize the needle as you normally would. 6. Place the cotton stack on top of the inoculation site, dry side down. 7. Press the needle through the stack and into inoculation site, and inoculate.
The needle penetrating through the alcohol, ideally slowly, would sterilize the outside of the needle at the point of entry into the jar or bag. The dry cotton would remove excess alcohol from the needle as it entered the container, as well as wiping away any remaining contaminants.
Perhaps this would help with possible contamination on the outside of the needle after flame and alcohol sterilization, i.e., between those sterilization procedures and the actual inoculation of the container.
Just an idea.
Edited by prajnaparamita (08/01/06 01:55 PM)
|
creamcorn
mad scientist


Registered: 03/13/06
Posts: 2,962
|
|
not a bad idea but i think you'll find it pretty tedious.
a clean work area, and working quickly when your needle is exposed, being careful not to let it touch surfaces, capping it when not in use, (read: use and apply common sense) already gives really high success rates.
its just as easy to take a piece of sponge, or paper towel soaked in alcohol, and use it like a sheath for the needle between innoculations. pull it out, quickly insert in the hole, quickly return it. gives near perfect results. a little excess alcohol on the outside of the needle isnt a problem that you need a provision to wipe it dry before inoculating.
|
dizzim
Born Again Head
Registered: 04/30/03
Posts: 238
Last seen: 9 years, 1 month
|
|
what about the possible contams on the plastic and dry cotton ball? you'd just be pushing these directly into the inoculation site.
|
prajnaparamita
Stranger

Registered: 07/22/06
Posts: 68
Last seen: 15 years, 9 months
|
Re: needle sterilization question [Re: dizzim]
#5921991 - 08/01/06 02:02 PM (17 years, 5 months ago) |
|
|
Presumably you would keep the cotton in sterile containers, and contaminants would die on the alcohol-soaked part, and would not be exposed to contaminants on the inside where the needle would be penetrating on the dry one. But if introducing a small amount of alcohol into the substrate isn't a problem, you could eliminate the dry cotton and the plastic separator.
|
creamcorn
mad scientist


Registered: 03/13/06
Posts: 2,962
|
|
the small amount carried on the needle is not a problem.
push a soaked cottonball up to the hole to poke through, and you'll probably drip a bunch in there. not so good.
still, why overcomplicate? as i mentioned, clean procedure, common sense = 99% success rate. inoculating isn't that hard, nor that 'critical' that you have to go so overboard. sure there's lots of contams in our air, but the needle is also very small, and only exposed to the air a few seconds at a time if you do things right. its really not an issue in the first place.
when its time to inoculate, i wash my hands, wash the counter, make sure anything like a fan or A/C that would cause drafts is turned OFF, and go to work. no fancy masks or gloves. i dont spray my house so full of oust i can't breathe (i dont even own a can of the stuff) i dont shower and run out naked or pray to my god beforehand or anything. i just use that little sheath method like i said, work quickly, and all is well.
flame the needle if its been used before, to ensure the inside is clean. if its a brand new sterile needle, i dont bother. its just a waste of time and gets the needle dirty with soot.
wipe down with alcohol between inoculations (or better yet just keep it protected with an alcohol soaked paper towel, like i said) so if you should contaminate something you don't cross-contaminate your jars, and voila, no problems.
keep it simple, less can go wrong that way.
|
FooMan



Registered: 02/02/05
Posts: 8,957
Loc: Earth
|
|
I've seen a couple people do variations of this already. I think Magash also did something similar to this. I use a cheap homemade glove box, but this method is good for open air inoculations.
--------------------
Quick WBS Prep
|
prajnaparamita
Stranger

Registered: 07/22/06
Posts: 68
Last seen: 15 years, 9 months
|
Re: needle sterilization question [Re: creamcorn]
#5922282 - 08/01/06 03:45 PM (17 years, 5 months ago) |
|
|
Quote:
creamcorn said: keep it simple, less can go wrong that way.
Yeah, keeping the needle in an alcohol sheath -- a sponge sounds like an especially good idea -- would probably work just as well.
But this isn't terribly complicated, either, and you could use the same barrier I described for multiple jars/bags. You can buy cotton squares at Wal-Mart which would work well for this, and if you doubled up with two dry squares on the bottom you could do away with the plastic, probably.
For people with persistant contamination problems, it might be something to add to their sterilization procedure.
|
|
|
You cannot start new topics / You cannot reply to topics HTML is disabled / BBCode is enabled
Moderator: Shroomism, george castanza, RogerRabbit, veggie, mushboy, fahtster, LogicaL Chaos, 13shrooms, Stipe-n Cap, Pastywhyte, bodhisatta, Tormato, Land Trout, A.k.a 1,733 topic views. 17 members, 183 guests and 40 web crawlers are browsing this forum.
[ Show Images Only | Sort by Score | Print Topic ] |
|