Consistent and efficient delineation of reference spaces for light microscopical stereology using a laser microbeam system

SUMMARY A serious problem in stereology is to ensure a consistent definition of reference spaces at different levels of magnification whenever the boundaries of such reference spaces are either fuzzy or non‐existent, and hence they have to be defined artificially. (It is well known that inconsistent definitions of the reference space leads to unknown amounts of bias in stereological results.) In this paper a new application is found for the laser microbeam system used in microdissection, whereby the required boundaries can be easily and neatly traced (in fact, cut) directly onto uncovered sections for light microscopy. The dangers of bias inherent from inconsistencies of definition are thereby eliminated completely, and alternative, very expensive procedures requiring direct marking of paper prints with a pen are no longer necessary.