Rapid microwave processing of skeletal muscle for TEM

Abstract

Rapid tissue processing for transmission electron microscopy is a desired goal in a clinical EM laboratory. Reducing the time from tissue submission to examination in the electron microscope shortens turnaround time for diagnosis. Microwave enhanced tissue processing will accomplish these goals.Microwave technology reduces the time for tissue fixation and processing and may improve overall results. Fixation times can be reduced from minutes to seconds and resin polymerization from hours to minutes. Dehydration and infiltration steps can also be reduced, so that microwave rapid tissue processing can yield ultrathin sections from unfixed tissue in three hours.Three microwave protocols to process skeletal muscle biopsies are compared to standard processing. The protocols test the efficacy of microwave fixation, dehydration, and resin infiltration and polymerization. Protocol #1 uses microwave enhanced 4:1 formaldehyde/glutaraldehyde primary fixation followed by routine processing for remaining steps. Protocol #2 uses microwave primary fixation and 2% OsO4 post-fixation followed by routine processing. Protocol #3 uses microwave enhanced processing for entire procedure. Protocol #4 uses the standard processing technique.