A secondary stage design for the preparation of microfossils for the SEM

Abstract. The preparation of microfossil specimens for study with the scanning electron microscope involves the transfer of material from slides to stubs. Specimens must then be oriented and mounted securely. To do this accurately the slide and stub should both be viewed through a stereomicroscope. However due to differences in shape and height, both surfaces are not usually in the plane of focus at the same time. Many micropalaeontologists routinely use small boxes or sample tube lids to hold the stub and refocus before finally mounting the specimens. The risk of dropping specimens is reduced by using a single carrier, securely holding both the slide and stub. The design illustrated below (fig.1) was developed from a prototype constructed from cardboard and plastic. The metal unit can easily be made in a workshop at a very low cost or cardboard versions made in the laboratory.

The stage is based on the principle that both slide and stub should be held securely, close together and in the same plane of focus. The slide holders should be secure but not too tight otherwise the stub may be jarred as slides are changed. The number of slides which can be held on one unit may be varied. The presence of two holders has proved useful, any more could make the unit cumbersome. If the microscope to be used does not have a wide stage then it may prove more practical to have only one holder.

The stub holders allow the stub to be clamped to . . .