Histopathology: Resin Embedding Media for Ultrastructure Study

Fixative solutions contain ______, and then a post fixation step with osmium tetroxide.

It is a twofold fixation, with glutaraldehyde preserving the cellular ultrastructure and osmium tetroxide retaining the ______ in the cell membranes.

Samples intended for resin embedding are much smaller than those for paraffin embedding. They are usually a few millimeters thick, because we are not interested in the general organization of tissues but in the ______ features of small regions.

If we want to study different regions of the same organ, it is recommended to obtain small pieces of each region we are interested in, and embed them in ______ resin blocks.

Most resins for embedding are not ______. So, the water must be removed from the sample and be exchanged with an organic solvent, the intermediary liquid.

Hardening of resin is not by cooling, but by ______, usually done at 60 °C.

For studying the ultrastructure of cells at transmission electron microscopy, we need very thin sections, less than ______ nanometers.

These very thin sections are obtained from very hard material using ______ microtomes.

Samples can be hardened by fast- and deep-freezing or, more frequently, by embedding the samples in ______.

______ resins are the most common embedding medium for electron microscopy studies.

The standard procedure for embedding with epoxy resins is similar to that described for ______ embedding.

Polymerization of epoxy resins proceeds usually at ______ ºC.