APPLICATION OF THE LOW VACUUM SCANNING ELECTRON-MICROSCOPE TO THE STUDY OF BIOMATERIALS AND MAMMALIAN-CELLS

The use of the scanning electron microscope (SEM) in 'low' (reduced) v acuum (Ivac) mode permits observation of specimens which have not been coated with a conductive material such as gold or carbon. We have eva luated the use of this mode of observation to the study of biomaterial s using the bone-substitute material Interpore as an example. On this material, rat bone cells were visible in Ivac mode only in cells trave rsing pores, when they were readily identified by their cell nuclei. R at calvarial bone examined uncoated in Ivac mode showed the bone struc ture clearly through the overlying layer of osteoblast cells, which we re subsequently revealed by gold coating. Immunogold labelling of alka line phosphatase was imaged in Ivac mode, following silver enhancement and carbon coating. These studies demonstrate the complementary use o f the Ivac and high vacuum (hvac) SEM to study material composition, t he behaviour of mammalian cells on biomaterials and the potential use of Ivac SEM to study mineralized tissues without removal of overlying soft tissue. (C) 1996 Elsevier Science Limited