[Neuroscience] Re: Vibratome squash

jonesmat via neur-sci%40net.bio.net (by jonesmat from physiology.wisc.edu)
Wed Mar 3 14:52:27 EST 2010


On Feb 19, 12:48 pm, Jason Jerome <hypa_d... from yahoo.com> wrote:
> I've been doing acute slice experiments for a couple years now and every
> other experiment I run in to this problem.
>
> When slicing, the brain appears to be squashed by the Vibratome blade before
> starting the cut. It seems like this reduces slice quality, but as you all
> know, methods to improve slice quality are often purely empirical and elude
> rationality.
>
> I use a slushy glycerol-based cutting solution but I have also used sucrose
> in the past with the same results.  I glue an agar wedge to the block as a
> support. The blade angle, speed, and amplitude are constant and are
> Vibratome's recommended settings for acute slices.
>
> I've heard that some labs partially cover the brain in a low, ultra-low, or
> normal gel-point agar (which is best is another question).  Does this
> substantially improve slice quality?
>
> --
> View this message in context:http://old.nabble.com/Vibratome-squash-tp27658614p27658614.html
> Sent from the Bio.net - Neur-sci mailing list archive at Nabble.com.


This sounds like a problem either with the blade or the slicer itself.
A good vibratome can make all the difference. In my experience the
best ones are the Leica VT series, and the Dosaka DSK.  I've had much
worse luck with the Camden-style slicers.

Some people swear by sapphire blades, but I have not found them
necessary (plus they're high maintenance, brittle and expensive). I
would, however, recommend using the thinnest, sharpest blades you can
get. We use the old fashioned *double-edged* shaving razor blades
(actually, we snip them in half with sharp strong scissors and use one
half at a time), and we use a fresh one for every prep. I do not
recommend any single edged blades, like box cutter or utility knife
blades. Too thick to make nice smooth cuts in my opinion. And
definitely never reuse a blade (unless its a sapphire blade).

Also. if the brain is allowed to wiggle around at all, you'll get
squishing. I wonder if your agar wedge is allowing too much wobbling?
We glue the brain directly to the block, and try not to let the tissue
be too "tall", if you know what I mean. If you really need the wedge
to get the right angle, you might try a stainless steel wedge or
something more solid.

Good luck,

Matt




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