There are many subcellular structures that can be confused with “viruses” in TEM images. These consist of coated vesicles, multivesicular bodies, exosomes, golgi and costomer-coated vesicles, etc. These structures/particles are sure to be within the sample as virologists fail to properly purify (free of foreign matter, pollutants, contaminants, etc.) and isolate (separated from everything else) the particles claimed to be “viruses.” To believe that they can look at sections from unpurified cell culture supernatant made up of nearly identical particles to identify a “novel virus” never before seen nor isolated is completely absurd.
This has led to some problems with studies claiming to find “SARS-COV-2” in tissues outside the respiratory tract. Certain researchers have claimed that they have TEM images of “SARS-COV-2” in various organs in the body outside of the respiratory tract, thus showing the “virus” does indeed replicate and spread throughout the body. However, numerous other researchers have stepped in to say “not so fast” as the particles claimed to be “SARS-COV-2” are in fact mimickers. They are subcellular structures which look like “SARS-COV-2” but due to their location, are not the “virus.” Confused? This article provides a nice overview of the particle blame game madness:
Hunting coronavirus by transmission electron microscopy – a guide to SARS-CoV-2-associated ultrastructural pathology in COVID-19 tissues
“Transmission electron microscopy has become a valuable tool to investigate tissues of COVID-19 patients because it allows visualisation of SARS-CoV-2, but the ‘virus-like particles’ described in several organs have been highly contested.”
“Physiological mimickers such as multivesicular bodies or coated vesicles serve as perfect decoys. Compared to other in-situ techniques, transmission electron microscopy is the only method to visualise assembled virions in tissues, and will be required to prove SARS-CoV-2 replication outside the respiratory tract. In practice, documenting in tissues the characteristic features seen in infected cell cultures seems to be much more difficult than anticipated. In our view, the hunt for coronavirus by transmission electron microscopy is still on.”
“Transmission electron microscopy (TEM) seems to be a logical tool to look for SARS-CoV-2 infection, but some of the published results are highly contested (kidney,8, 22 endothelium,8, 9, 23–28 intestine,8 liver29–32 and placenta33–37).”
“Pathologists are good at detecting some viral infections – at least in identifying unusual inclusions on a haematoxylin and eosin (H&E)-stained slide. However, unless there is a knowledge of virus morphology (what they look like) and morphogenesis (how and where in the cell they are assembled), it is difficult to identify them. Depending on the virus, we use immunohistochemistry targeting viral proteins or in-situ hybridisation to highlight their DNA or RNA. Molecular pathology techniques allow us to test for viruses in tissues when in situ techniques are not yielding results. All these techniques have been applied successfully in the context of SARS-CoV-2 (Figure 1;5, 38, 39). It is important to note that any of these tests require an a priori notion of what is present; otherwise, it is difficult to choose the right reagent (e.g. if a herpesvirus is suspected and an anti-herpesvirus antibody is used, but the infection is caused by an adenovirus, then the test is negative and the diagnosis is no closer to being made).”
“Currently, our knowledge of the morphological changes associated with COVID-19 infection is mainly based on autopsy tissue obtained from severely affected individuals in the pulmonary or hyperinflammatory phase, making it difficult to differentiate between changes driven by local viral replication, changes due to the systemic inflammatory response and repair, or possibly therapy effects. Indisputable detection of SARS-CoV-2 by TEM would confirm viral replication outside the upper respiratory tract and lungs and firmly establish a role of direct viral infection to some of the organs mentioned above.”
“Frequently, the centre of the viral cross-section is electron lucent. Unless a negative staining procedure for viewing viruses in fluids or tannic acid staining of tissue for thin sections is used, the S proteins forming the ‘corona’ are not readily discernible.98“
“Others, including some of us, have reported on ‘virus-like particles’ by TEM not completely matching the cell culture findings in a variety of organs, including lung,5, 8, 26, 56, 102, 104 kidney,5, 8, 10–12, 23, 104 liver,29 heart,104 intestine,8, 103 skin71 and placenta.33, 36, 69, 70 Colleagues have rightfully raised their concerns that these particles are not consistent with SARS-CoV-2,14–18, 34 but depict other subcellular structures, making identification of SARS-CoV-2 by TEM much more challenging than expected.”
Morphological mimickers of SARS-CoV-2
“Physiological structures including coated vesicles, multivesicular bodies and cross-sections of the rough ER are morphological lookalikes of genuine coronaviruses.105
Coated vesicles (CV) are single membrane-bound vesicles of variable size (typically 50–150 nm) characterised by ‘spiny adornments on their limiting membrane’ (Ghadially106) (Figure 4E). They are involved in endocytosis and membrane trafficking (reviewed in Robinson107).
In clathrin-coated vesicles, the best-studied example, the CV bud off from so-called coated pits on the cell surface during micropinocytosis. Clathrin and other quantitatively minor proteins provide a three-dimensional structural lattice, which is readily seen in electron micrographs. Morphologically identical structures with coats provided by the main proteins, COPI or COPII, are involved in transport processes of the trans-Golgi network.
Internalisation of SARS-CoV-2, after binding to its receptor ACE2, involves this mechanism.46, 47 While CV may transport viral proteins, as shown for vesicular stomatitis virus,108 and may be used for replication of poliovirus109 and, further, have a similar size to that of coronavirus, they are not the assembled virus itself. However, although the projections appear as a perfect ‘corona’ in cross-sections, CV lack the nucleocapsid present inside coronavirus cross-sections, and they are located within the cytoplasm and not within vacuoles.
Multivesicular bodies (MVB) are other structures of the endosomal pathway visible by TEM (Figure 4F) (reviewed in Huotari and Helenius110). They consist of a round or oval vacuole (250–1000 nm) with a limiting membrane, and depending on the density of the matrix, a light or dense background. The larger vacuoles contain multiple smaller membrane-confined intraluminal vesicles (ILV) with a diameter of 50–100 nm.”
“MVB are the perfect ‘decoy’ for electron microscopists searching for viral particles. Some of us have been misled by them in our COVID-19 autopsy series5 because the ILV have a similar size to SARS-CoV-2 and are located within vesicles.”
“In COVID-19 tissues the ER is frequently swollen, and the accumulation of membrane structures further adds to the confusing ultrastructure (Figure 4C). A cross-section through rough ER can easily be mistaken for a ‘virus-like particle’, but these are located within the cytoplasm and not in vesicles and lack the nucleocapsid structures inside.
In kidneys from COVID-19 autopsies, we encountered a peculiar subcellular structure closely mimicking SARS-CoV-2 but probably related to the ER (Figure 4C,G–I).5, 13 Larger vesicles with a smooth outside membrane contained several round to oval small vesicles with prominent electron-dense granules on the inside. These granules were bigger than SARS-CoV-2 nucleocapsid seen in our infected cell cultures and had the same size as the ribosomes visible in areas containing rough ER (ribosomes: 20–21 nm (range = 17–23 nm) versus nucleocapsid: 12 nm (range = 9–16 nm). These vesicles with ‘outside-in’ ribosomes are possibly derived from the rough ER by membrane invaginations, as suggested in some of the TEM pictures (Figure 4I). Because the particles inside are larger than nucleocapsid cross-sections, we believe that they probably do not represent assembled virions. However, it is theoretically possible that the particles may consist of deteriorated and swollen nucleocapsid due to autolysis, approaching the appearance of ribosomes.”
“The published in-vivo data are less convincing. Coated vesicles, multivesicular bodies and swollen rough endoplasmic reticulum are important mimics of assembled virions, all of which lack the electron-dense dots of the nucleocapsid inside the particles. High magnification (~×90 000) is required to clearly identify them. Autolysis of autopsy tissue further adds to the difficulty of identifying viral particles by TEM.”
- Researchers have claimed to find “SARS-COV-2” in TEM images from tissues in the body but the ‘virus-like particles’ described in several organs have been highly contested
- Physiological mimickers such as multivesicular bodies or coated vesicles serve as perfect decoys
- The researchers state that documenting in tissues the characteristic features seen in infected cell cultures seems to be much more difficult than anticipated
- They believe that the hunt for “coronavirus” by transmission electron microscopy is still on
- Published results of TEM images of “SARS-COV-2” in various organs (kidney, endothelium, intestine, liver and placenta) are highly contested
- Unless there is a knowledge of “virus” morphology (what they look like) and morphogenesis (how and where in the cell they are assembled), it is difficult to identify “viruses”
- It is important to note that any of the molecular tests require an a priori notion of what is present; otherwise, it is difficult to choose the right reagent
- It is difficult to differentiate between changes driven by local “viral” replication, changes due to the systemic inflammatory response and repair, or possibly therapy effects
- Indisputable detection of “SARS-CoV-2” by TEM would confirm “viral” replication outside the upper respiratory tract and lungs and firmly establish a role of direct “viral” infection to some of the organs mentioned above (in other words, there has been no indisputable detection of “SARS-COV-2 in these organs)
- Unless a negative staining procedure for viewing “viruses” in fluids or tannic acid staining of tissue for thin sections is used, the S proteins forming the ‘corona’ are not readily discernible
- Others, including the authors of this paper, reported on ‘virus-like particles’ by TEM not completely matching the cell culture findings in a variety of organs, including lung, kidney, liver, heart, intestine, skin and placenta
- Colleagues have rightfully raised their concerns that these particles are not consistent with “SARS-CoV-2,” but depict other subcellular structures, making identification of “SARS-CoV-2” by TEM much more challenging than expected
- Physiological structures including coated vesicles, multivesicular bodies and cross-sections of the rough ER are morphological lookalikes of genuine “coronaviruses”
- Clathrin-coated vesicles, may transport “viral” proteins, and may be used for replication of “poliovirus” and, further, have a similar size to that of coronavirus, although they are not the assembled “virus” itself
- Their projections appear as a perfect ‘corona’ in cross-sections
- Multivesicular bodies (MVB), are the perfect ‘decoy’ for electron microscopists searching for “viral” particles
- They have a similar size to “SARS-CoV-2” and are located within vesicles
- A cross-section through rough Endoplasmic Reticulum (ER) can easily be mistaken for a ‘virus-like particle’
- In the kidneys, they encountered a peculiar subcellular structure closely mimicking “SARS-CoV-2” but probably related to the ER
- Because the particles inside are larger than nucleocapsid cross-sections, they believe that they probably do not represent assembled “virions”
- They conclude that coated vesicles, multivesicular bodies and swollen rough endoplasmic reticulum are important mimics of assembled “virions”
- Autolysis (the destruction of cells or tissues by their own enzymes, especially those released by lysosomes) of autopsy tissue further adds to the difficulty of identifying “viral” particles by TEM
In the above article, they admit that unless the “viral” morphology and morphogenesis is known, it is difficult to identify “viruses” by way of TEM. They also admit that in order for molecular tests to be accurate, there must be a priori knowledge of the “virus” present otherwise selecting the right reagent is difficult. “SARS-COV-2” is said to be a novel “virus.” It was never purified/isolated. Thus, there is absolutely no way they would have any knowledge about morphology nor morphogenesis. They would not be able to select the right reagent to detect it through molecular testing. The original researchers assumed they were dealing with a “Coronavirus” and built everything from “knowledge” of other “coronaviruses” which were also never properly purified/isolated. It is fraud built upon fraud.
It is very apparent that what is identified in TEM images is based on guesswork and assumptions made by the subjective interpretation of the person viewing the images.