An improved method for preparing thick sections for immuno/histochemistry and confocal microscopy and its use to identify rare events

Detection of rare events within solid tissues by immunocytochemistry is aid ed by imaging thick sections. Sections of 40-100 mum thickness of paraforma ldehyde-fixed solid tissue can be prepared by use of a vibrating microtome and when immunolabelled these sections can be imaged in a confocal microsco pe. This approach provides excellent preservation of the structure of the s ample and imposes minimal antigenic damage. In studies of the invasion of t he bovine intestinal epithelium by Salmonella, this method has allowed dete ction of individual invading bacteria within large samples. The thick vibra ting microtome sections were also used for the detection of rare apoptotic cell nuclei identified by TUNEL staining.