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    Professor Chossudovsky Is Wrong - Here Is How PCR Tests Work MoA Archived Message

    Posted by Tomski on October 13, 2020, 9:48 pm

    Chossudovsky's article was discussed here a while back. I think MoA puts a nail into that coffin.

    https://www.moonofalabama.org/2020/10/professor-chossudovsky-is-wrong-here-is-how-pcr-tests-work.html#more

    The website Global Research provides at times interesting reading. It is edited by Michael Chossudovsky, an emerited professor for economics. Unfortunately he at times writes about issues that are beyond his horizon.

    In a recent piece, The Covid-19 Numbers Game: The “Second Wave” is Based on Fake Statistics, he falsely claims that the tests which are globally used to detect SARS-CoV-2 infections also react to other viruses and thereby deliver false results.

    The method of the currently used SARS-CoV-2 test is based on the reverse transcription polymerase chain reaction (RT-PCR). The polymerase chain reaction can create millions of copies of RNA or DNA snippets fed into it:

    Polymerase chain reaction (PCR) is a method widely used to rapidly make millions to billions of copies of a specific DNA sample, allowing scientists to take a very small sample of DNA and amplify it to a large enough amount to study in detail.
    ...
    Thermal cycling exposes reactants to repeated cycles of heating and cooling to permit different temperature-dependent reactions – specifically, DNA melting and enzyme-driven DNA replication. PCR employs two main reagents – primers (which are short single strand DNA fragments known as oligonucleotides that are a complementary sequence to the target DNA region) and a DNA polymerase.
    A clinical probe is taken from a human who may have the virus. In a preparation phase the probe is chemically cleaned and the outer hulls of viruses in it get destroyed. What is left includes the genetic material of the virus.

    The genes of the SARS-CpV-2 are an RNA sequence with roughly 30,000 nucleotides. It is like a book with 30,000 characters on how to build the virus. It is unique for this virus. The researchers who developed the SARS-CoV-2 RT-PCR test have selected several about 100 nucleotides long snippets out of the much longer string. Complementary oligonucleotides of the same length will then get synthesized. These are the primers for all following PCR tests.

    The cleaned sample (10 to 200 µL), the primers and the polymerase are fed into a machine. Repeated cycles of heating and cooling will each multiply the number of RNA snippets in the sample. Luminescent markers are added to get an automatically readable result. Typically some 20-25 cycles are needed to detect the virus RNA snippets of an acute infection. When more cycles (typically up to 40) are used even a minimal amount of a specific virus RNA snippet can be detected. The process is highly automated.

    Chossudovsky has not understood how the above process works. Specifically he has not understood that the selection of the oligonucleotides for the primer is very specific to the type of virus the test is supposed to detect.

    Thus he is wrong when he writes:

    According to Dr. Pascal Sacré, “these tests detect viral particles, genetic sequences, not the whole virus”
    What this means is that the PCR test cannot detect or identify SARS-CoV-2. What it detects are fragments, which suggests that a standard “PCR positive” cannot be equated to a so-called Covid-19 Positive.

    The PCR test will pick up fragments of several viruses including corona viruses as well as influenza (flu viruses A and B)

    While SARS-2 which causes Covid-19 is considered to be similar to SARS-CoV-1, it has similar symptoms to seasonal influenza (Viruses A and B). Moreover, some of its milder symptoms are similar to those of the common cold corona viruses. According to the CDC: “Sometimes, respiratory secretions are tested to figure out which specific germ is causing your symptoms. If you are found to be infected with a common coronavirus (229E, NL63, OC43, and HKU1), that does not mean you are infected with the 2019 novel coronavirus.”

    According to the CDC there are “seven [human] coronaviruses that can infect people” the first four of which (alpha, beta) are associated with the common cold.
    ...
    In the above context, what this means is that a PCR test will pick up fragments of corona as well as influenza viruses. It will not be able to identify individual viruses including SARS-2.

    “Fragments of viruses positive” does not mean “SARS-2 positive” (or Covid-19 Positive). The PCR test may pick up fragments of influenza viruses (A, B) as well as common cold beta coronaviruses (e.g. OC43, HKU1).

    This highlighted passages are as wrong as one can possibly get it wrong. The RT-PCR tests for SARS-CoV-2 DO NOT detect other types of viruses.

    We know this because the folks who developed the test the WHO recommends to use have written about their development process:

    We downloaded all complete and partial (if > 400 nt) SARS-related virus sequences available in GenBank by 1 January 2020. The list (n = 729 entries) was manually checked and artificial sequences (laboratory-derived, synthetic, etc), as well as sequence duplicates were removed, resulting in a final list of 375 sequences. These sequences were aligned and the alignment was used for assay design (Supplementary Figure S1). Upon release of the first 2019-nCoV sequence at virological.org, three assays were selected based on how well they matched to the 2019-nCoV genome (Figure 1). The alignment was complemented by additional sequences released independently on GISAID (https://www.gisaid.org), confirming the good matching of selected primers to all sequences.

    The selected oligonucleotide assays, each specific for a certain snippet of the SARS-CoV-2 virus RNA, were then tested for their sensitivity and chemical stability.

    They were also tested for cross-reactivity with other viruses:

    Cell culture supernatants containing all endemic human coronaviruses (HCoV)‑229E, ‑NL63, ‑OC43 and ‑HKU1 as well as MERS-CoV were tested in duplicate in all three assays (Table 2). [..] Additional undiluted (but not quantified) cell culture supernatants were tested as summarised in Table 2. These were additionally mixed into negative human sputum samples. None of the tested viruses or virus preparations showed reactivity with any assay.

    In total 297 clinical samples with 23 different human virus types in them were tested. The newly developed assays developed to find only SARS-CoV-2 reacted with none of those.

    Etc.



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