A grinding problem

jimbo ferguson at oci.utoronto.ca
Mon May 16 11:54:47 EST 1994

In article <1994May16.045337.13334 at midway.uchicago.edu>, 
sferguso at kimbark.uchicago.edu (Stacy Ferguson) writes:

> In article <2qlrn5$n3r at bigboote.WPI.EDU> jbagshaw at wpi.WPI.EDU (Joseph 
> C. Bagshaw) writes: 
> >This is my second attempt to post this message.  The first did't 
> >get through, I'm a novice, and the local college computer center 
> >speaks no known human language.  Sorry for the noise. 
> > 
> >I have a problem for which someone out there may have a solution. 
> >I need to prepare genomic DNA from frozen tissue (shrimp tails, 
> >to be specific).  The first step is to reduce the tail muscle, 
> >still frozen, to as fine a powder as possible.  Currently, I wrap the 
> >tail in two or three layers of foil, place it on a metal block 
> >on dry ice, and pound it with a hammer.  This reduces the tail to 
> >small chunks, which I then grind in a mortor and pestle on dry ice 
> >until my arm aches.  From there on the DNA extraction in a breeze, and 
> >I get super quality DNA.  This crude but effective pulverizing method 
> >is OK for a limited number of samples, but the prospect of doing a few 
> >dozen shrimp this way is pretty daunting.  I'm looking for an 
> >alternative that would facilitate rigorous grinding of 
> >multilpe samples.  Any suggestions would be appreciated. 
> > 
> >Joe Bagshaw 
> >Department of Biology and Biotechnology 
> >Worcester Polytechnic Institute 
> >Worcester, MA 01609 
> >jbagshaw at wpi.wpi.edu 
> > 
> >********************HAVE GENES, WILL TRAVEL******************** 
> > 
> > 
> First, I'm glad to see you're using a part of the shrimp that most 
> people don't eat anyway. I'd hate to see good shrimp go to waste :) 
> Will a Waring Blendor work? You can usually find them in big scientific 
> supply catalogues like Fischer, Baxter, etc. You can buy small blender 
> cups for scientific use. I've made liver powders and things like that 
> using frozen tissue and dry ice for DNA preps. The only problem with 
> this is that the cups aren't cheap, so if you plan on doing pcr or 
> something where minor contamination would be a huge problem, then it 
> would be prohibitively expensive to buy one cup per prep. The cup I 
> used held about 50 ml but I know they come in smaller sizes. 
> Stacy 

I used to know someone who extracted plant metabolites in a mortar and pestle 
along with liquid nitrogen.  She said that this made the frozen plant 
material more brittle than dry ice did.  You could give it a try.

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