PREPARATION OF LARGE BIVALVE SPECIMENS FOR SCANNING ELECTRON MICROSCOPY USING HEXAMETHYLDISILAZANE (HMDS)

Abstract

Treatment with hexamethyldisilazane (HMDS) for drying specimens for Scanning Electron Microscopy (SEM) is described for relatively large (>20 mm shell height, SH) individuals of two scallop species, Placopecten magellanicus and Argopecten irradians. The traditionally used method of critical point drying (CPD) has been applied successfully for smaller specimens (~350 μm up to 15 mm SH); however, occasional rupture of the mantle occurred in these specimens. Furthermore, size limitation of the CPD chamber did not permit preparation of larger individuals. An alternative experimental protocol using HMDS was tested, which successfully preserves the morphology of the bivalve feeding organs, mantle surface and the cilia of the two scallop species with negligible shrinkage and few artifacts. Another benefit of this method is that the number of specimens and sample size is not restricted.