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General Category => Yeast and Fermentation => Topic started by: enso on February 04, 2010, 05:13:56 PM

Title: Loop vs. needle?
Post by: enso on February 04, 2010, 05:13:56 PM
So, I just streaked my first plates.  Fun!   ;D

I used my inoculation loop as most sources I have read instruct.

I have an inoculation needle though as well.  In my eagerness to get going I placed an order with more beer and got their overpriced needle.  This was before I learned about cynmar.  So now I have both and I am not sure what the needle is for.

What I have read indicates that the loop is for streaking plates and slants and the needle is for stabs.  I don't understand the purpose of a stab though.  I get that you stab the inoculated needle into the agar in a slant, but what does that do?  How do you then work with this?
Title: Re: Loop vs. needle?
Post by: Kaiser on February 04, 2010, 05:21:12 PM
stab cultures tend to remain viable longer since the yeast grows inside the agar where it doesn’t have access to oxygen. I had a few cases of 12+ month old yeast where the slant culture was dead but the stab culture still had live cells which I was able to culture on a plate and then in new slants and stabs.

Kai
Title: Re: Loop vs. needle?
Post by: enso on February 04, 2010, 05:30:08 PM
Okay thanks. 

How do you then access this yeast inside the agar to propagate it?
Title: Re: Loop vs. needle?
Post by: Kaiser on February 04, 2010, 05:31:58 PM
How do you then access this yeast inside the agar to propagate it?

stab the needle in it a few times and then streak it over the plate. That's what I do and it seems to work. You don't really have to stab exacly into the hole you made first. There seems to be enough viable yeast throughout the agar.

Kai
Title: Re: Loop vs. needle?
Post by: Thirsty_Monk on February 04, 2010, 07:12:42 PM
Thank you for the info.
I also have both loop and needle but so far I used loop only.
Title: Re: Loop vs. needle?
Post by: dean on February 04, 2010, 07:16:51 PM
Do I "need" a loop, or will the needle suffice?   ???
Title: Re: Loop vs. needle?
Post by: Thirsty_Monk on February 04, 2010, 07:20:25 PM
I think needle could do the job.
Title: Re: Loop vs. needle?
Post by: dean on February 04, 2010, 07:28:33 PM
I hope so, I'm going to try streaking soon... who was it that wrote the song "they call him the streak?"   Don't looook Ethel!   :D
Title: Re: Loop vs. needle?
Post by: roffenburger on February 04, 2010, 07:56:11 PM
Do I "need" a loop, or will the needle suffice?   ???

You can make a loop from your needle. Just wrap the end of your needle into a loop. You can use a nail or something similar to help form it.
Title: Re: Loop vs. needle?
Post by: dean on February 04, 2010, 09:08:20 PM
Quote
You can make a loop from your needle. Just wrap the end of your needle into a loop. You can use a nail or something similar to help form it.

After reading that I took a closer look at the needle.  The part that I thought was a handle on it is actually a slip on cover over the needle which is a fine wire... so I guess I can make a loop.   Prior to this I had only looked at it inside the case and I thought the fat wire was the needle... wow this thing has a long handle on it and the needle part is probably 3 to 4 inches long.  Thanks for making that post... it made me take a closer look at it.   :)
Title: Re: Loop vs. needle?
Post by: Hokerer on February 04, 2010, 09:11:19 PM
who was it that wrote the song "they call him the streak?"   Don't looook Ethel!   :D

You mean Ray Stevens?  here...

http://www.youtube.com/watch?v=85krLPrWWTY (http://www.youtube.com/watch?v=85krLPrWWTY)
Title: Re: Loop vs. needle?
Post by: enso on February 04, 2010, 09:44:01 PM
One last questions on stab cultures.  I would suppose then that it is not necessary to prepare the vials for this on a slant?  Meaning, one would simple pour the agar solution into the vial, sterilize, and then let cool standing straight up?
Title: Re: Loop vs. needle?
Post by: Kaiser on February 04, 2010, 10:51:51 PM
Yes, that's what I do.
Title: Re: Loop vs. needle?
Post by: enso on February 05, 2010, 01:05:56 AM
Many thanks Kaiser!

Slàinte Mhath!