Diagnostic electron microscopy on reembedded ("popped off") areas of large Spurr epoxy sections.

A technique is described in which areas of large Spurr epoxy thick sections are directly popped off of glass slides by inverted Beem capsules filled with polymerized plastic. This technique allows the survey of large regions of tissue with the maintenance of tissue relationships and the selection of specific areas for electron microscopic studies. Within the context of diagnostic electron microscopy well-preserved and representative portions of tissues can be selected as well as individual diagnostic cells or other difficult to find structures. Many small pieces of minced, optimally fixed and processed tissue can also be surveyed by this technique. Thus, one can screen the equivalent of 20 or more standard thick sections in one step. This "pop-off" technique does not appear to alter the ultrastructure of the tissue in any way.