In a message dated 99-02-03 11:06:28 EST, nasimas@khi.compol.com writes:

<< Can anyone tell me about the issue sriking my mind ..
 Can Electron microscopy be done on formalin fixed paraffin emebedded tissue.
 Ahme
  >>

Ahme,

Yes, you can do this, but the ultrastructural preservation in the specimen
will probably not be very good.  It all depends on the quality of processing
during the initial paraffin embedding, which is usually quite rapid.  If this
is the case, you will likely only see remains of membranes, cellular outlines
and nuclear "ghosts," and not much intracellular detail.  Extracellular matrix
materials may survive the process well enough to distinguish collagen,
elastin, etc.

1.  Cut away as much of the paraffin from the specimen as possible.

2.  Remove the remaining paraffin by incubating in xylene.  Use several
changes of xylene over 3-4 hours or overnight.

3.  Incubate in 100% alcohol, 3-4 changes, 20 minutes each to remove the
xylene.
At this point you can cut up the specimen if necessary into the sizes that are
normally used for EM (0.5-1.0mm cubes, or as small as possible).

4.  Partially rehydrate the specimen by using stepwise alcohol dilutions,
returning to about 50% or 70% alcohol in water.

5.  Re-dehydrate and process into plastic as you normally do.

Good luck, hope this helps.

Bob
******************************
Robert (Bob) Chiovetti, Ph.D.
President
Microimaging Technologies, Inc.
Tucson, Arizona USA
Tel./Fax (520) 546-4986
rchiovetti@aol.com
Manufacturers' Representatives
Systems Integrators
Analog & Digital Imaging Systems
Clinical & Research Microscopy
Cytology/Histology/Pathology/EM
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