[Histonet] tissue-tek mega cassettes

[Gayle Callis]

Carol,

My long standing frustrations will be showing up in this message with what 
I consider an engineering problem.

I have never found a mega cassette that fits in any of my microtome block 
holders. I have tried so many of them and they were ALL painfully 
useless.   I listened to various vendors and tried their sample so 
generously supplied to the lab, but their mega cassettes failed to fit in 
the microtome holder.   I have actually spent time comparing a regular 
cassette design to a mega cassette design, how they fit in the holder - it 
was an interesting exercise since they do NOT fit the same way although 
they LOOK the same.

I've groused about this over the years one one with vendors. But nothing 
has changed since the mega cassettes are still a poor, loose fit in the 
holders.  I have had them fall OUT onto my blade !@#%!@$@#$ with vertical 
orientation and slide side to side with horizonal orientatio  My mega 
cassettes were made by Sakura many years ago but these have never been a 
good fit in my holders but then no other vendors have worked either.  I 
don't know how much vendors test this product, but many histotechs have 
experienced the problem.  Histonet has some extensive discussion on this so 
it is not a new problem that has been around for years.  Our lab gave up 
using them except for processing large whole rat knees, whole mouse heads, 
or oversized tissues. They are tossed in the garbage at embedding to use 
another setup with large Peelaway molds and regular cassette backs which 
produces a firmly held, stable block at sectioning.

I am ever hopeful one will be manufactured that truly fits in a holder (ALL 
HOLDERS) and does the job!  I wish you luck in finding the product, and if 
you do, let us know.

Gayle Callis HTL, HT, MT(ASCP)
Research Histopathology Supervisor
Veterinary Molecular Biology
Montana State University
Bozeman MT 59717




At 01:10 PM 11/15/2006, you wrote:
>Hello,
>
>
>
>I've been purchasing from Sakura the tissue-tek mega cassettes.
>
>I use the HM355S Microm microtome.
>
>These cassettes were the only ones I could find to purchase that fit the 
>microtome chuck.
>
>I tested several other makes all were loose fitting and caused sectioning 
>problems.
>
>
>
>Sakura has changed the design of their tissue-tek mega cassettes.
>
>They no longer fit snuggly in the chuck.  If you put the block in 
>horizontally or vertically
>
>it does not fit correctly.
>
>
>
>Has anyone else had this problem?
>
>
>
>If I use a piece of small cardboard, like the old days, it wouldn't work.
>
>The vertical measurement is too short for a snug fit.
>
>
>
>I need a mega cassette that fits snuggly in the chuck.  Does anyone 
>purchase these
>
>without this problem?
>
>
>
>May I please have the name of your source?
>
>
>
>Any vendor who sell mega cassettes 1 ½ " by 1" and ½" deep  please send me 
>some
>
>samples to test.
>
>
>
>Any help would be appreciated.
>
>
>
>Thank you,
>
>
>
>Carol Ann Bobrowitz
>
>Medical College of Wisconsin
>
>Department of Physiology
>
>MEB RM #4940
>
>8701 Watertown Plank Road
>
>Milwaukee, Wisconsin   53226
>
>
>
>cbobrowi <@t> mcw.edu
>
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