A grinding problem

littgj at wmvx.lvs.dupont.com littgj at wmvx.lvs.dupont.com
Mon May 9 18:16:17 EST 1994

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********************
I believe what you want is a ball mill. This is simply a
ceramic "jar" (not unlike a mason jar used in the old days
to preserve things) with a very secure top and a series of
balls (ceramic, stainless stell, etc) inside. In your case,
the frozen sample, pellets of dry ice and the balls are added
and the jar is rotated on a simple roller device (like those used
in the photographic darkrooms to develop color prints). I'm not
sure where you obtain these things but they are widely used
in the pharmaceutical industry in a variety of sizes. You
probably can rig something up if you can find a strong (non
peeling!) container.

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