Low Voltage Electron Microscopy in Cell Biology Research
The world continues responding to COVID-19 with incredible human spirit and scientific breakthroughs. In unprecedent speed, the crystal structure has been mapped, new vaccines are in Phase I human clinical trials, and the time the virus remains viable on various common surfaces has been quantified (van Doremalen, 2020). As cell biology research continues to be of great societal important, this piece highlights the broader ways low voltage electron microscopy has accelerated virology and cell biology research by linking to the abstracts of important articles in recent years.
LVEM5 Advantages in Cell Biology Research
The LVEM-5 has demonstrated capabilities in cell biology and in virology research. Using a lower accelerating voltage allows for higher contrast of carbon-based materials and low-Z materials found in biological organisms. Proteins, lipids, and structures made from these materials are easier to image quickly compared to traditional TEM with higher accelerating voltages. The small laboratory footprint allows for placement of a TEM in a traditional cell biology laboratory, eliminating the need for costly dedicated imaging facilities, and increasing the ability to rapidly analyze samples. Perhaps one day, a benchtop LVEM5 will be as common as light microscopes in research labs.
LVEM5 Helps Identify Plant Virus
Researchers in Florida were able to identify a plant virus in the article “First Report of Frangipani Mosaic Virus Infecting Frangipani (Plumeria spp.) in the U.S.A” (Dey et al, 2020). The LVEM-5 was used to examine the sap from a set of plants exhibiting unknown disease symptoms when initial genetic analysis failed to identify a cause. The rod-like shape and dimensions of the viruses found in the sap led to confirmation with additional genetic analysis.
Obtaining High Quality Biological Specimen Images
Many factors influence the ability to obtain high quality images of biological specimens via low voltage electron microscopy (Sintorn, 2013). From sample preparation and deposition, to choosing whether to use staining techniques and which ones are appropriate, to the use of gold-nanoparticle tagged antibodies for observing protein expression, literature exists to guide researchers to common best practices.
Figure: Example micrographs of cellular structures obtained with a LVEM5.
References:
Bendayan M, Paransky E. Low voltage transmission electron microscopy in cell biology. Progress in histochemistry and cytochemistry. 2015 Jul 1;50(1-2):1-0. https://doi.org/10.1016/j.proghi.2015.05.001
Dey K, Velez-Climent M, Soria P. First Report of Frangipani mosaic virus Infecting Frangipani (Plumeria spp) in the USA. Plant Disease. 2019 Dec 26(ja). https://apsjournals.apsnet.org/doi/full/10.1094/PDIS-09-19-2003-PDN
Sintorn IM, Nordström R, Haag L, Coufalova E, Drsticka M. Factors influencing high quality low voltage TEM imaging of biological routinely stained specimen. InMicroscopy Conference (MC) 2013 2013 (pp. 321-322). http://www.diva-portal.org/smash/record.jsf?pid=diva2%3A678193&dswid=8620
van Doremalen N, Bushmaker T, Morris DH, Holbrook MG, Gamble A, Williamson BN, Tamin A, Harcourt JL, Thornburg NJ, Gerber SI, Lloyd-Smith JO. Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1. New England Journal of Medicine. 2020 Mar 17. https://www.nejm.org/doi/full/10.1056/NEJMc2004973
About the author:
Robert I. MacCuspie, Ph.D., has over twenty years of experience in nanotechnology and materials characterization, at national laboratories, academia and corporations, working at the interface of business and science.