In this note we show the potential usefulness of glutaraldehyde (GA) in confocai microscopic studies of wood-fungal interaction. We are presently developing methods to examine by the confocai laser scanning microscope (CLSM), the pattern of distribution of fungal hyphae within wood in relation to fungal degradation and sapstaining of wood. CLSM has the potential to be a very useful tool in such studies for a variety of reasons, including its use for optical sectioning to produce computer assisted 3-D images.