recovery of polymerized mass
I am not familiar with the Leica embedding medium but if I remember
correctly the medium is GMA. The first thing to do whether it is GMA or
MMA is to remove the mass from the container, then trim as much of the mass
away using a band saw. More than likely the cassettes are at the bottom
of the mass. When you trim be very careful not to cut into the tissue
specimens. It will take quite awhile depending on the size of the mass to
recover the specimens but it can be done.
GMA RECOVERY, place the mass in a gauze bag and suspend the trimmed mass in
95% ethanol and stir on a magnetic stirrer. The GMA will soften and can be
peeled away (it will be gooey). Keep checking the mass every couple of
days and change the alcohol as well.
MMA RECOVERY, place the mass in a gauze bag and suspend the trimmed mass in
stock MMA and stir on a magnetic stirrer. The MMA will dissolve the mass
over time. Again check the mass and periodically change the MMA stock
Eventually you will get down to the specimens. Once the specimens are
recovered you can complete the processing schedule. Be patient. It will
take time but your specimens can be recovered.
Back in the 80's I was infiltrating tissues and had a container with
cassettes in it that had 1000 ml of GMA. When I checked on my specimens
Monday morning I discovered to my horror that the infiltrating medium had
polymerized. I did not panic however, because I had experienced the
problem previously with MMA. Although it took awhile I was able to
completely recover the specimens, complete the process and section the
blocks (even wrote a paper on it).
Anyway, good luck. Hopefully the investigator will understand that it is
recoverable but will take time and patience.
GLP Compliant Laboratory
Cathy A. Mayton
Wasatch Histo Consultants, Inc.
<< Previous Message | Next Message >>