Name: Review of Paper: Electron Microscope Preparation for COVID-19 "Virus"
Uploaded: 2023-06-26T18:46:26+00:00
Duration: 11 min 12 s
Description: In this video I go further into the main paper on COVID-19 "virus" isolation and this time review the paper's methods on transmission electron microscopy (TEM) preparation. TEM involves firing a beam

2 years ago

170

covid-19 covid electron microscopy transmission electron microscope virus sample preparation virus pandemic coronavirus science stem virology

In this video I go further into the main paper on COVID-19 "virus" isolation and this time review the paper's methods on transmission electron microscopy (TEM) preparation. TEM involves firing a beam of electrons through an ultrathin section and the resulting interactions with the sample forms an image that can then be made visible through fluorescent screens or other methods. But to get to this point, the sample is typically first mixed with many heavy metal chemicals and embedded into a resin block. This means that any biological samples will be dead and heavily processed.

For this paper, the first sample prepared was the supernatant of the "infected" human airway cell cultures that showed "cytopathic effects" (CTE), and was then "virus inactivated" with a chemical preservative and ultracentrifuge at around 100,000 RPM. The resulting sedimented "virus" particles was then heavy metal stained on film-coated metal grids.

The second sample was the "infected" airway cell cultures (that showed CTE) themselves, and they were "fixed" with heavy metal preservatives, dehydrated with alcohol, and then embedded in a resin block before being cut to tiny nanometer slices for TEM.

This is a very complex process to somehow see dead particles assumed to be "virions"...

The paper is listed below:

- A Novel Coronavirus from Patients with Pneumonia in China, 2019
- Authors: Na Zhu et al
- Published on January 24, 2020 in The New England Journal of Medicine (NEJM)
- https://www.nejm.org/doi/full/10.1056/NEJMoa2001017

The timestamps of key parts of the video are listed below:

- Paper Methods: Electron Microscope Preparation: 0:00
- Virus Inactivation, Paraformaldehyde, Fixation: 0:49
- Ultracentrifuge, Transmission Electron Microscopy (TEM), Heavy Metals: 1:41
- Fluorescence, Electrons, Electromagnetic Radiation (EMR), Aether: 2:29
- TEM Schematic: 3:22
- Enriched Supernatant Was Negatively Stained: 4:18
- Negative Stain, Staining, Film-Coated Grids, Hydrophilic, Formvar Grid: 5:06
- Fixing Airways Cells Showing Cytopathic Effects: 6:22
- Glutaraldehyde, Osmium Tetroxide, Grade Ethanol: 6:54
- PON812 Resin, Viscosity, Embedding: 7:31
- Ultrathin Sections Cut from Resin Block: 8:27
- Nanometers, Uranyl Acetate, Lead Citrate: 8:51
- Summary of Electron Microscope Preparation: 9:10