Joycee,

     I am speaking from a "Leica"  background which includes the old brand
names of AO,  B&L, LKB,  Leitz, Jung  and Reichert. All of these old
companies  made sliding/sledge  microtomes. The AO 860 (1945 to 1988) is
probably the most commonly found "Slider"  in the US.

     1. The sliding microtome (where the blade travels over the specimen)
is generally limited to a couple of inches in paraffin. If you cut larger
specimens the blade has a tendency to "dive" into the specimen. This could
give you a section a micron thicker at the end of the cut than the
beginning. The sledge microtome (where the specimen travels under a fixed
blade) can fasten the blade at both ends and is easier to stabilize than
the "slider".  Our motorized sledge, the Polycut E, can handle an 25CM X 20
CM specimen and will cut and feed automatically from 1 micron to 999 micron
with the muscle to pull through  anything softer than its carbide blade.
Our current instruments on the more routine approach would be the HS 2000R
and the SM2400.

     2. Custom slides and cover glass are available from the slide and
cover glass mfg.

     3. Most schools have a "slider"  tucked in a closet somewhere. The
biggest challenge to the life of these instruments is rust. Since the
technique to use these microtomes tends to be esoteric and cumbersome, very
few if any are used  for routine clinical applications.
Best regards,
Don

Don Birgerson
Application Specialist
Leica-Microsystems
Technical Assistance Center
1 800 248 0123  ext 5918