Submitted to: Microscopy and Microanalysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2018
Publication Date: 8/1/2018
Citation: Mowery, J.D., Bauchan, G.R. 2018. Optimization of rapid microwave processing of botanical samples for transmission electron microscopy. Microscopy and Microanalysis. 24:1202-1203. https://doi.org/10/1017/S1431927618006499.
Interpretive Summary: Preparing biological samples for transmission electron microscopy (TEM) is hindered by the slow rate of diffusion of reagents into tissues, resulting in procedures that typically take 3-4 days to complete. Microwave irradiation can speed up the rate of diffusion allowing the entire process to be completed within a few hours. A new rapid microwave protocol is presented for preparing plant samples for TEM. These new methods not only significantly reduced the processing times, but they helped preserve important cellular structures like chloroplasts, mitochondria, Golgi bodies, and nuclei. These results are important to electron microscopy experts, botanists, horticulturists, plant virologists, and agricultural scientists in the government, at universities, and in private industry who are interested in methods to prepare plant tissues for examination by transmission electron microscopy.
Technical Abstract: Processing biological samples for transmission electron microscopy (TEM) using conventional processing methods are hindered by the slow rate of diffusion of reagents into the tissue, resulting in procedures typically taking 3-4 to complete. Microwave irradiation drastically speeds up the rate of diffusion allowing the entire process to be completed within a few hours. However, modern microwave systems have improved considerably in recent years creating a need for revised protocols, especially for plant specimens which typically require additional processing steps. A new optimized rapid microwave protocol is presented for preparing plant samples for TEM, utilizing the Pelco BioWave Pro Plus microwave system, examining leaf tissue from tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum). Utilizing these methods, not only significantly reduced the processing times, but also slight improvements were observed in the preservation of the ultrastructural morphology of various organelles in tomato and tobacco leaves compared to conventional processing. Morphological enhancements were detected using microwave polymerization compared to conventional oven polymerization. In some cases, small improvements may still be possible to reduce the time of this microwave procedure even further. More work is needed to fully compare all the ultrastructural variations between conventional and microwave processing across a wide range of plant tissue.