Some have suggested surface cuts, embeddment of threads, or even the inclusion of some kind of stainable implant.

Thank You in advance for any and all comments.

KWB
BAKERK@AA.WL.COM

I have been thinking about a similar problem with respect to serial sectioning of the hippocampus. Could the use of a microbeam laser to produce a micron-size hole in the tissue be part of a solution?

Leo Marin
leo@spine.med.utoronto.ca

Dear Leo & all,

Since the object is to produce contrast between the rest of the section and the fiducial mark, a micron-sized hole would do the job. One must remember that during the fixing, staining & embedding the hole might be bent or otherwise distorted, but that information is useful in itself. An alternative to using a laser is to use a micropipette. We have been developing micropipettes for HVEM sample holders & have discovered that they can be pulled to submicron diameters, so they may offer an advantage over lasers. (Good old low-tech solutions still have merit. :-))

Yours,
Bill Tivol
tivol@wadsworth.org