Good point Barry

-----Original Message-----
From: Barry R Rittman [mailto:Barry.R.Rittman@uth.tmc.edu]
Sent: Tuesday, July 08, 2003 9:49 AM
To: histology
Subject: RE: deplasticizing MMA sections


Julee

I think that the discussion about thickness of plastic sections raises
an important point, namely how to get the information you want from
these sections.
It is technically difficult and requires considerable skill and time to
consistently produce very thin plastic sections. The perception of
course is that resolution dictates "the thinner the section the better".
However, thicker sections (routine ground or plastic) have an important
place in histology. As has been pointed out, the surface of the sections
can be etched and stained. Using incident light microscopy the upper few
microns can be used to form the image.  As reflected light generally
only penetrates a few microns into hard tissues,  you can have your cake
and eat it as only the upper few microns are used to form the image.
Many studies in histology have used thick sections, stained the upper
few microns and then once the information is recorded have repeated
polishing the surface, staining upper layers and so on. This is similar
to the advantage of serial sections. 

Thick sections can also be examined either unstained or stained using
other types of microscopy, optically sectioned  e.g. Differential
Interference Contrast, Hoffman Modulation, Confocal, Deconvolution
Microscopy etc. 
Thick sections, whether ground or paraffin, while generally not
providing the same degree of resolution,  can be very useful in
providing a better overall concept of tissue relationships than thin
sections. 
In the search for better resolution, I hope that histologists remember
that in studying tissues there is a place for both thin and thick
sections.
Barry