Transmission electron microscopy (TEM) freeze substitution of plant tissues.

INTRODUCTION: Transmission electron microscopy (TEM) requires extensive preparation of plant tissues to achieve optimal results. Samples must be fixed to preserve ultrastructure, dehydrated to withstand the high vacuum of an electron microscope, and embedded in a suitable resin to permit very thin sections to be produced. This protocol describes freeze substitution of plant tissues. It provides better conservation of certain intracellular components, including microtubules and membranes, than do the standard sample preparation procedures for TEM.