SEM Quick Start
Revision No.2
May 2014
Page 4 of 16
are all fairly simple. Perhaps the most convenient instrument used
to deposit spots on the support is the mechanical micropipette. The
exact volume of the spot will naturally vary depending on the
situation. It is advisable to test different sample volumes on a
separate surface prior to deposition on a support film.
Occasionally the use of a micropipette proves to be rather
unwieldy and the task requires different methodology. It has been
found that simply using the disposable plastic tips of the
micropipette as a spotter is a viable alternative. Glass spotters can
be used to some degree of success, but have found to be a rather
poor alternative to the aforementioned methods.
1.1.2.2
Solid Samples
Samples that are solid are most commonly dissolved or
suspended in an appropriate solvent and mounted the same as
liquid samples (Section 1.1.2.1). Samples that cannot be dissolved
or suspended practically are attached to their support using either a
conductive tape or a conductive paste as adhesives. It is advisable
to refer to the instructions specific to the adhesive being used
before utilizing them. Note that pastes and adhesives are not used
when operating in STEM modes.
1.1.3
Loading the Carousel
Once prepared, sample supports are fixed to an appropriate grid
carousel capable of holding several films simultaneously. These sample
carousels come in many different styles and are what ultimately interface
with the microscope’s stage platform. All carousels are fixed to the stage
via a dovetail joint. One end of the joint on the stage platform has a flat
docking bar that articulates with the flat end of the grooves found on the
bottom of the sample carousel. It is important to ensure that the carousel is
seated correctly before continuing. This precaution will both reduce the
likelihood of collision happening within the vacuum chamber and increase
the ease in which samples can be located on the support carousel using the
STEM Navigation tool (Section 1.3.3).
