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A synthetic corundum knife for ultrathin sectioning *
Author(s) -
Hodgson Clague P.,
Cunningham William P.
Publication year - 1987
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.1987.tb01331.x
Subject(s) - corundum , materials science , sapphire , cleavage (geology) , scanning electron microscope , aluminium , crystal (programming language) , synthetic diamond , diamond , microanalysis , mineralogy , composite material , optics , chemistry , fracture (geology) , laser , physics , organic chemistry , computer science , programming language
SUMMARY A synthetic corundum (Al 2 O 3 , synthetic ruby, synthetic sapphire) knife has been constructed which is suitable for the preparation of thin sections (less than 90 nm) of biological specimens for electron microscopy. The method involved cleavage or fracture of the flame‐fusion crystalline product, followed by mounting in a standard knife holder for ultramicrotomy. The cutting edge appeared flawless under 400 × and produced sections in which subcellular organelles were clearly resolved. Scanning electron microscopy of the knife revealed conchoidal fractures typical for corundum, terminating in apparent cleavage of the crystal along the knife edge. X‐ray microanalysis of the knife edge revealed essentially 100% aluminium, indicating that the aluminium oxide crystal was of a high purity. The superior toughness and low cost of synthetic corundum suggest that it may be a useful alternative to diamond or glass knives.