C-shaped dipper: A novel useful auxiliary tool for preparation of specimen grids for transmission electron microscopy.

Abstract

The transmission electron microscopy (TEM) has played a pivotal role in visualizing and detailing the morphology of nanoscale objects of observation, but care must be taken to ensure that the object is in its original, unperturbed state. This is because not all objects under the observation are necessarily robust and structurally stable, and if the object being observed is so delicate and easily changeable in shape, one may be observing structural artifacts leading to wrong interpretations. I here present a novel prototype of an easy-to-use and reliable auxiliary tool, the C-shaped dipper, developed for the preparation of specimen grids for TEM, along with its handling instructions for diverse applications. Some nanostructures are so delicate and fragile that their nanocomplexes are easily destroyed when aspirated by a pipette with a narrow tip diameter. Using the C-shaped dipper, the observation objects can be scooped up in a droplet formed by the surface tension of the liquid, keeping their intact shapes, and placed on a grid precovered with a support film. The C-shaped dipper has proven to be excellent for handling soft assemblies having delicate structures, such as nano-scale composites, for facilitating thin layered formations with molecular constituent blocks, and for preparing a grid individually covered with a collodion film or an amorphous carbon support film.