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High Resolution Scanning Electron Microscopy in Biology: Artefacts Caused By the Nature and Mode of Application of the Coating Material
Author(s) -
Bråten Trond
Publication year - 1978
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.1365-2818.1978.tb00093.x
Subject(s) - sputtering , materials science , coating , scanning electron microscope , evaporation , palladium , composite material , nanotechnology , metallurgy , chemistry , thin film , biochemistry , physics , thermodynamics , catalysis
SUMMARY Results of high resolution secondary electron observations of the haemocyanin molecule from the marine whelk Buccinum undatum are given. The choice of metal used for surface coating of the sample (gold, gold‐palladium or carbon/gold‐palladium) and the mode of application of this metal (thermal vacuum evaporation or diode sputtering) were both found to be of utmost importance when working at high magnifications in the scanning electron microscope. Sputter coating with gold gives poor results because of a granular and cracked appearance of the surface film. The haemocyanin molecules were difficult to recognize in these preparations. Best results were obtained by a thermal vacuum evaporation of gold‐palladium. It is suggested that the inferior results seen after sputter coating may be due to the high temperatures which the specimen experiences during the sputtering, even when cooling of the specimen stage is carried out. Other specimens (diatom valves and latex spheres) were also studied at high magnification giving the same results as the haemocyanin molecules.