scanning electron microscopy preparation Dr. Jastrow's electron microscopic atlas

Vocabulary
of micros-
copic
anatomy
specialist terms
explained in
English +
German

Every attempt was made to provide correct information, however any liability for eventual errors in the protocol is rejected

dieser Seite

Editor:
Dr. med.
H. Jastrow

Conditions
of use

Technique of specimen preparation for scanning electron microscopy
Foreword:
To investigate material in a scanning electron microscope (SEM) it has to have the following characteristics:
high resistency under vacuum, no change under electron beam, it may not have disturbing charges, must generate enough secondary electrons and has to show a clean surface.

Method (example):
- perfusion fixation of tissue using 1 - 3 % buffered glutaraldehyde pH 7.2 - 7.4
- wash and postfix in 1 - 2 % buffered osmium tetroxide pH 7.2 - 7.4
- wash in distilled water.
- dehydration (10 minutes each) in aceton 30 % - 50 % - 70 % - 90 % - 95 % - 95 % - 100 % - 100 % - 100% (thereby the specimen must not get in contact with air)
- position specimen in the pressure chamber of a critical point dryer
- wash 8 - 10 x with fluid CO₂
- dry at 73.8 bar and 31°C on critical point (here the massive phase directly turns to gaseous phase in order to avoid any surface tension on the specimen)
- slowly remove CO₂
- immediately fix the specimen on the specimen holder using kolloid silver solution
- put specimen in sputter-coating machine for cathode beam sputting with gold
- put the ready specimen in SEM for investigation

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--> Electron microscopic atlas Overview
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