title: A simple technique for the examination of urothelial surface morphology by transmission electron microscopy: platinum-carbon replicas of critical point dried bladder tissue.
abstract: A simple technique is described for the examination of bladder luminal surface morphology by transmission electron microscopy (TEM). Pieces of bladder tissue are critical point dried and replicated with platinum-carbon in the manner standard for freeze-fracture. The large intact areas of replica produced show improved resolution of detail compared with scanning electron microscopy (SEM), and allow the survey of larger expanses of membrane than is possible with standard TEM techniques. Comparison of the structure observed in platinum-carbon replicas of critical point dried tissue with that seen in frozen-surface replicas, freeze-fracture replicas and thin-sections reveals the presence of artefacts in the critical point dried specimens which are not detected by SEM. Similar artefacts are evident in replicas of partially freeze-dried samples. The nature and origin of these artefacts are discussed. It is concluded that replicas of critical point dried specimens provide useful information on surface morphology at magnifications intermediate between those normally used with standard TEM and SEM techniques. The details of surface morphology viewed by this method are discussed with particular reference to the structure of the intercellular boundary.
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000648:ultrastructure; D003890:Desiccation; D004848:Epithelium / Q000648:ultrastructure; D005615:Freezing; D008854:Microscopy, Electron / Q000379:methods; D051381:Rats; D013048:Specimen Handling / Q000379:methods; D001743:Urinary Bladder / Q000648:ultrastructure*