5 ms·

> Anything over 35 is a worthless test that's a false positive. That's not a false positive. False positive happens when there are no viral particles in the sa

> Anything over 35 is a worthless test that's a false positive. That's not a false positive. False positive happens when there are no viral particles in the sample, but the test comes back positive. Those are very rare with rt-PCR and can usually be tracked down to cross-contamination. Cycle count has nothing to with those. If there is no SARS-CoV-2 genetic material in the sample, there's nothing for rt-PCR to amplify.

sleepysysadmin 6y ago
>That's not a false positive. False positive happens when there are no viral particles in the sample, but the test comes back positive. Those are very rare with rt-PCR and can usually be tracked down to cross-contamination. Cycle count has nothing to with those. You're not arguing with me. You are arguing with Fauci. https://youtu.be/a_Vy6fgaBPE?t=231 https://youtu.be/a_Vy6fgaBPE?t=231 If you could explain to me if you don't mind. Why are you saying Fauci is wrong? Was he lying again? >If there is no SARS-CoV-2 genetic material in the sample, there's nothing for rt-PCR to amplify. I made my entire post literally Fauci and not me at all. I made no comments or assertions.
- sobriquet9 6y ago
  Here Dr. Fauci is answering a different question: whether a patient with positive rt-PCR test result is still infectious (shedding virus that is replication capable). rt-PCR test cannot distinguish between live, replication-capable SARS-CoV-2 and its remains, or inactivated copies. It detects short snippets of genetic material, not the entire virus.
  - sleepysysadmin 6y ago
    I think we have come to a complication. My understanding of his words and the situation is what I posted. Yes they are talking about shedding the virus but it doesnt change the subject. You can read much more in depth about why there was a bad cycle #. At the time of creating the rules they didn't have a real copy of the infected person. They simulated it. https://www.fda.gov/media/134922/download https://www.fda.gov/media/134922/download It was a mistake on their part, but the reasoning is irrelevant here. Mistakes are going to happen during a crisis. The problem is the ongoing pattern of lying. I genuinely people like Tam and Fauci are trying to the do the right thing but it sets for extreme levels of distrust by lying. The next pandemic may be much worse because we simply lost trust in experts because they lied.
    - sobriquet9 6y ago
      I'm not saying that Dr. Fauci wasn't lying. He was, about masks, about washing hands, about "no evidence" of virus being airborne, about length of lockdown, etc. I'm just saying that this particular argument, about cycle count and false positives, is not one of those cases.
deleted 6y ago
[deleted]
reedjosh 6y ago
> That's not a false positive. "Moreover, positive real-time reverse transcription (rRT)-PCR test results that are close to the limit of detection (LOD) of an assay have a greater likelihood of being false positives. One key explanation for this is that when specimens become contaminated with very low levels of test target during the laboratory testing process, it produces a high Ct positive result near the assay LOD." https://www.publichealthontario.ca/-/media/documents/ncov/main/2020/09/cycle-threshold-values-sars-cov2-pcr.pdf?la=en https://www.publichealthontario.ca/-/media/documents/ncov/ma...
spookthesunset 6y ago
PCR tests have very low false positives. If you've got a tiny spec whatever genetic material the machine is set to amplify... it will happily do so. The intent of covid tests isn't to see if you have a tiny insignificant spec of SARS-CoV-2 in your nasal passage. The intent is to see if you have Covid19 and are possibly contagious. When you amplify too much, you are defeating the purpose of the test. A tiny spec of remnant SARS-CoV-2 doesn't mean you are contagious or have Covid19. It just means you have a tiny spec of viral material up in your nose.
- sobriquet9 6y ago
  That's why COVID-19 is diagnosed not only by rt-PCR, but also on the basis of symptoms, chest CT scans, and other nucleic acid testing.
- cameldrv 6y ago
  The problem is that you may be in an early stage of infection where there isn't much virus, or the swab may not have caught much of it. You could also have already recovered from an asymptomatic infection, and there is some residual viral RNA. A high Ct could be because of one of those factors, or from cross-contamination.

sleepysysadmin 6y ago

>That's not a false positive. False positive happens when there are no viral particles in the sample, but the test comes back positive. Those are very rare with rt-PCR and can usually be tracked down to cross-contamination. Cycle count has nothing to with those. You're not arguing with me. You are arguing with Fauci. https://youtu.be/a_Vy6fgaBPE?t=231 https://youtu.be/a_Vy6fgaBPE?t=231 If you could explain to me if you don't mind. Why are you saying Fauci is wrong? Was he lying again? >If there is no SARS-CoV-2 genetic material in the sample, there's nothing for rt-PCR to amplify. I made my entire post literally Fauci and not me at all. I made no comments or assertions.

sobriquet9 6y ago
Here Dr. Fauci is answering a different question: whether a patient with positive rt-PCR test result is still infectious (shedding virus that is replication capable). rt-PCR test cannot distinguish between live, replication-capable SARS-CoV-2 and its remains, or inactivated copies. It detects short snippets of genetic material, not the entire virus.
- sleepysysadmin 6y ago
  I think we have come to a complication. My understanding of his words and the situation is what I posted. Yes they are talking about shedding the virus but it doesnt change the subject. You can read much more in depth about why there was a bad cycle #. At the time of creating the rules they didn't have a real copy of the infected person. They simulated it. https://www.fda.gov/media/134922/download https://www.fda.gov/media/134922/download It was a mistake on their part, but the reasoning is irrelevant here. Mistakes are going to happen during a crisis. The problem is the ongoing pattern of lying. I genuinely people like Tam and Fauci are trying to the do the right thing but it sets for extreme levels of distrust by lying. The next pandemic may be much worse because we simply lost trust in experts because they lied.
  - sobriquet9 6y ago
    I'm not saying that Dr. Fauci wasn't lying. He was, about masks, about washing hands, about "no evidence" of virus being airborne, about length of lockdown, etc. I'm just saying that this particular argument, about cycle count and false positives, is not one of those cases.

deleted 6y ago

[deleted]

reedjosh 6y ago

> That's not a false positive. "Moreover, positive real-time reverse transcription (rRT)-PCR test results that are close to the limit of detection (LOD) of an assay have a greater likelihood of being false positives. One key explanation for this is that when specimens become contaminated with very low levels of test target during the laboratory testing process, it produces a high Ct positive result near the assay LOD." https://www.publichealthontario.ca/-/media/documents/ncov/main/2020/09/cycle-threshold-values-sars-cov2-pcr.pdf?la=en https://www.publichealthontario.ca/-/media/documents/ncov/ma...

spookthesunset 6y ago

PCR tests have very low false positives. If you've got a tiny spec whatever genetic material the machine is set to amplify... it will happily do so. The intent of covid tests isn't to see if you have a tiny insignificant spec of SARS-CoV-2 in your nasal passage. The intent is to see if you have Covid19 and are possibly contagious. When you amplify too much, you are defeating the purpose of the test. A tiny spec of remnant SARS-CoV-2 doesn't mean you are contagious or have Covid19. It just means you have a tiny spec of viral material up in your nose.

sobriquet9 6y ago
That's why COVID-19 is diagnosed not only by rt-PCR, but also on the basis of symptoms, chest CT scans, and other nucleic acid testing.
cameldrv 6y ago
The problem is that you may be in an early stage of infection where there isn't much virus, or the swab may not have caught much of it. You could also have already recovered from an asymptomatic infection, and there is some residual viral RNA. A high Ct could be because of one of those factors, or from cross-contamination.