Reproducibility and applicability of gallium replication as evaluated by biological specimen use

Structures of biological surfaces pressed on to a pure liquid gallium surfa ce were successfully traced on to the gallium surface by quick-freezing bel ow the melting point (28.78 degrees C) in air or water for replication in s canning electron microscopy. Gallium's high surface tension (similar to 700 mN m(-1) at 30 degrees C) deteriorates the spatial resolution of replicas and destroys some types of specimens. Five different biological surfaces we re replicated on to gallium surfaces to evaluate spatial resolution and spe cimen resistance, i.e. reproducibility and applicability. Gallium replicati on of jewel beetle wing and human hair demonstrated submicron spatial resol ution in the horizontal direction at least. Trials of protozoa, bacteria, a nd culture cell replication showed that protozoa are suited to replication because the cell membrane has characteristic structures with sufficient res istance to the gallium surface.