For a layman, this is the clearest explanation of RT-PCR testing I have seen. Thanks. A little explanation of the use of temperature in PCR machines during each stage of each cycle would add something that is missing from the video, I feel.
I 'm a nursing student from Nepal. Thank you so much for your explaination .I received the explanation that I was so excited to know.Thank you so much ❣
You can also look at a guy call Shomu from india talking about CT values ..I just went over that video as my dad is covid positive with a CT value of 22 . Trust me that video gave me so much information ! You can check that out . It's a 30 minute video but talks in so much detail If you are really into how this is done .
Precisely speaking the accuracy of test depends upon: 1. Sample and VTM 2. Type of kit used in the pcr process (Standardized). 3. Technician who takes the charge of operating the entire PCR process. 4. Clinician/Physician who evaluates and interprets the result with the clinical presentation of the patient. Thanks
Don't be so naive. Investigate the CT values in association with this test. The cycle number should be under 30-35, anything beyond that and it becomes a false positive. Because it starts to detect dead Covid particles and other Coronaviruses with similar DNA. The inventor of the PCR said it needs to be under 25 cycles and should not be used for virus diagnosis.. WHO - world health organisation has set this cycle limit to 40-45! There is now a 90%+ false positives rate..
I had gone for the RTPCR test. Gave my sample in 2 laboratories on the same day. The result was different from both the laboratories. One was negative and one was positive. Now I understand why. Thanks for the info :)
What you and many others fail to understand and this example avoids telling you is thatKaryMullins the inventor specifically said that the PCR testing is not meant for nor reliable for diagnosing any specific disease. There are actual diagnostics for that. Many are running the cycles so many times, especially beyond 10 until it will give you a positive test result.
@@ronparcke-wms2146 Mullis invented PCR not RT-PCR! The RT-PCR test is merely to determine if you have the RNA from the virus! Like any test, it along with other criteria (e.g. symptoms), can be used to confirm the diagnosis. your comment "Many are running the cycles so many times, especially beyond 10 until it will give you a positive test result" is wrong. Most people believe at a ct of 33, if positive it means you have active virus in your body. cts greater than that most likely means you have been infected in the past with the virus and the RNA present does not indicate the virus is active. That is not a false positive as the test is testing for the presence of the RNA not whether you are suffering from the disease at the time!
I'm going to travel and read that a RT-PCR test is important and I didn't knew it's meaning And now I'm here... I have all the knowledge and I'm a mad scientist
What about vthe creator of this PCR test? What you and many others fail to understand and this example avoids telling you is that KaryMullins the inventor specifically said that the PCR testing is not meant for nor reliable for diagnosing any specific disease. There are actual diagnostics for that. Many are running the cycles so many times, especially beyond 10 until it will give you a positive test result.
@@JayTaylor3dollarfilmsgenerally speaking once the RT-PCR goes over 30--35 cycles it starts detecting dead Covid fragments and other Coronaviruses with similar RNA leading to a very high number of false positives. As much as 90%. False positives are obviously misleading especially if they are considered just "positive" without any clarification on cycle numbers. Quite often a positive result will not come with its cycle number recorded. So there are few stats showing it to give is any perspective. To put this into perspective, the inventor of the PCR test Kary Mullis "apparently" said only 25 cycles is sufficient. (There is video of him saying this somewhere). It was never originally intended for testing but for manufacturing purposes.. Kary always maintained it wasn't suitable for virus diagnosis, especially "live infectious" virus diagnosis. He conveniently died in the middle of 2019 just before *event 201* (the practice run) and subsequent Wuhan outbreak. Although we can never fully verify this as medical investigators were not allowed into Wuhan even after China reports showed it had died out. Despite modern advancements it still seems vulnerable to misinterpretation and misuse. There are also the quick tests and other types of tests recently manufactured & being used based on PCR. It seems they may still be vulnerable to misinterpretation if not adhering to a strict agreed cycle protocol as the final prognosis. The following link is a recent peer review of the reports/paper's that originally gave the RT-PCR tests the green light for world wide use for Covid 19: cormandrostenreview.com/retraction-request-letter-to-eurosurveillance-editorial-board It's worth more investigation.
@@rickknight3823 40 cycles, math 1.0995 x 10 to the twelfth power or 1,099,500,000,000 strands. You tell me at this point how infectious is this person. More multiples become less accurate. And which virus of the thousands of molecules that we all have in us at any given time is the RNA from Sars connected to. No way of knowing, sorry, that is the facts. John T. above, correct the PCR is for research only not clinical diagnosis. Ask Mr. Mullis, he might know something. We've been played..........
@@bposkier51 @The B yes I completely agree with you. I'm not sure if that got lost in translation. More cycles of course mean it becomes far too sensitive if one was to "try" and use it effectively. I posted the Corman Drosten peer review of the original recommendations for the RT-PCR test in the thread above - demanding for it's immediate withdrawal from public use. cormandrostenreview.com/retraction-request-letter-to-eurosurveillance-editorial-board/
Question: Since a foreign swab is going into the nasal tract. How likely is that the swab is infected and in turn infects the patient being tested even if he/she was not COVID positive earlier? But gets the infection through the swab? Do answer. Thanks.
The Ct value is important. The positive result means nothing regarding if the Ct is not provided. The assay is very important! The DNA probes used in real time RT-PCR are only about 25 bases long; the FDA says using 100 bases is desirable. To say false positives are mainly clinical errors is disingenuous and completely false.
Yeah, and a Ct of 45 (like the WHO recommended and then magically changed their mind on the day of Joe Biden's inauguration) is going to be returning a LOT of false positives.
@@brianmcnutt8850 recommend is a thing... the cycles the labb chose is another thing.... recommendations isn't a law..... it's only a guideline but every laboratory chose their rutines.
@@astrosurf68 Laboratories were told to increase the CT for unvaccinated individuals. You can find the directives from the CDC, emailed to laboratories and hospitals.
The virus itself is broken down along with other things in the sample. In that sample the viral RNA is isolated and purified in a different process not mentioned. Primers that are specific to that cDNA made (that became from viral RNA) is then used to begin PCR. These primers are specific to certain genes of the viral genome. We know this because the virus genome has already been sequenced.
In your video at 5m 28sec you said that a person with a CT of 10 would have 1 million more viral particles than a person with a CT of 30 - did you mean to say 1 billion as that is what a CT30 score would equate to? Thanks in advance for confirming.
Wow. Wonderful explanation. Explaining science concepts is something that takes practice and making someone to spend few mins and getting them to understand needs some serious skill. Came here to know how RTPCR testing works. Seems there's tons of other valuable contents in this channel to explore.
Tested positive and am asymptomatic with no current interactions with positive individuals . I was never given a ct value in my report from the biologixi test through the saliva test
An appeals court in Portugal has ruled that the PCR process is not a reliable test for Sars-Cov-2, and therefore any enforced quarantine based on those test results is unlawful. Further, the ruling suggested that any forced quarantine applied to healthy people could be a violation of their fundamental right to liberty. Most importantly, the judges ruled that a single positive PCR test cannot be used as an effective diagnosis of infection.
The judges are in trouble over this. Their decision was illegal, they were not competent to accept that process, let alone make a decision on it.. (Translated) _The Superior Council for the Judiciary, the regulating body of judges, will take to plenary the judgment signed by two judges on confinement in the Azores. Judges are subject to prosecution._ observador.pt/2020/11/18/juizas-da-relacao-que-apreciaram-confinamento-nos-acores-levam-processo-disciplinar/ More here (Translated) _Judges from the Lisbon Court of Appeal misread two scientific articles and the scientific consensus on PCRs is “absolute”, experts react._ www.publico.pt/2020/11/17/sociedade/noticia/juizas-fazem-leitura-errada-artigos-cientificos-poe-causa-fiabilidade-testes-covid19-1939616
If PCR isnt reliable test then tell us which test is reliable.We will all do that test.If you dont know any such test,PCR is the single best,most specific and sensitive test.Talking about human rights,other people have right to live healthy.They dont deserve to be infected with this deadly virus.So when you test positive for SARS COV-2 stay in home quarantine,isolate yourself and let other people live.
@@gaurabgurung9232 I have the right to walk down the street healthily but all these negligent drivers keep hitting pedestrians! 😱 I don't deserve to be infected with their deadly C.A.R.S. virus! Incidents involving automobiles take too many lives each year, it's time we ban these killing machines! Your right to drive does not outweigh my right to LIVE!!! Give your drivers license & car to your Govt. They know what's best for you, you know it's for the greater good.
Violation of Law of Leviticus. Check out Leviticus 13. Symptoms determined when someone is sick and needs to be quarantined. No symptoms means no quarantine. No symptoms means Clean. Clean without masks, vaccines or PCR Tests. Same for masks. Prolonged, enforced masks to restrict breathing was never God's intention.
is C19 a disease? NO, it's a "virus" that causes the diseases, does those diseases have a cure? YES, so why panic. most people will do just fine, and please stop calling this a "deadly" virus, cars are deadly, stairs are deadly, smoking is deadly, Dont drag others to live in fear.
Thank you so much for your explanation.. And I have a question... when I want to make RT-PCR for a specific gene, how can I know the experiment conditions such as: the period of time and temperature for each cycle as well as the number of microliter for each reaget( primers, mister mix, ...)???
Not good enough. PCR uses two primers, that anneal to two specific zones of the target genome. The primers are only 20-30 nucleotides or bases long. The low number of nucleotides on the probes renders the PCR test's specificity EXTREMELY LOW in an un-purified sample. In short, the PCR test protocols won't differentiate between SARS-CoV-2, fragments of old SARS RNA, influenza A & B, or other genetic garbadge, floating around in your snot sample. Turn up the temperature cycles > 40 and the number of FALSE POSITIVES will rocket. Verdict: FRAUD
It's annoying because I was a Director at a RT-PCR lab that did classic non-modified testing(is there a more proper name for the classic test?) and all the jacka**' including female friends who were shouting "false positives" not once mentioned false negatives and were telling me that they knew better than I when I was the head of a RT-PCR testing lab. They really have Dunning Krueger and it was very frustrating and stressful all because they had a belief system and a culture they wanted to signal they were a part of. I genuinely don't understand the tribal lack of genuine curiosity when it comes to topics in science. Science doesn't have a side, it just is and that's how it should stay.
@@maxiglad1624 You're probably talking about the antigen tests not the PCR and you pulled the 9/10 statistic out of your ass (never mind all your numbers). I also dont find anything related to the 500 doctors on google? The only problem with pcr tests are false negatives, if you test positive, you are positive.
Stop doing it. It's a scam! Kerry Mullis the inventor even confirmed PCR test aren't made for testing viruses. All PCR test have Graphine Oxide. Look it up. Share the info and stop complying!
Investigate the amount of cycles those samples are put through the RT-PCR test.. Anything above 30-35 and you get 90%+ false positives . WHO have set this to 40-45!
As you probably know, there is a maximum of 25 to 30 cycli allowed to get a credible result. In the PCR test for Cov they do 45 (although he says 40). Which is way over the maximum and thus yes, you are correct, this is a fraudulent surogate technique. But this is only one of the 12 big issues that are wrong with the PCR covid test. A retraction paper against the original paper that resulted in PCR test for covid is nearly complete and will be submitted this wednesday.
Yes, these days all PCR testing uses real time PCR also known as qPCR or quantitative PCR also known as real time quantitative PCR. Real time PCR means that the amplification can be seen in real-time by measuring the fluorescence throughout the test. This allows you to quantify the amount of target DNA present in the sample, as shown in the video. RT-PCR is Reverse-transcription PCR and is used when you need to detect RNA viruses such as SARS-CoV-2, as you need to convert the RNA to cDNA first. RT-PCR and qPCR are not mutually exclusive. When you are using RT-PCR for a test, you would be using qPCR. Sometimes this is called qRT-PCR, but these days the q is often left off because it is assumed that if you are amplifying for the purpose of a diagnostic test, you must be using real time methods.
Isn't it interesting that the inventor him self said using this method does not show you have a virus or not. Yet we are still using this method to stack "Case" numbers against the rights of the public. References upon request.
As the video explains, the amplification process releases a dye. A laser is used to detect fluorescence in the tube. Once the fluorescence is detected, that sample becomes positive.
sure, why not? Your result is going to come back "positive" anyway, unless they already have so many positives that they have to call you a "negative" to simulate some kind of credible results.
Depends on what you're testing for. SARS-CoV-2 is a respiratory virus, so you would generally test from nose or throat. Depending on what you're testing for, you could use PCR with any material that contains DNA, such as blood, skin, semen, bone, fingernails, hair, organs, etc.
is it possibile that primers attach to an erroneus cDNA create a FALSE positive ? are the PRIMERS very accurate or not ? what is the error rate with this kind of test ?
There is very low likelihood of something like that happening if the primers are correctly manufactured and utilized. A false positive may happen if you had contamination, where a false negative may happen if not stored properly or there is a delay in testing. The error rate is correlated with the time after infection that the test is taken, the errors giving false negatives go up the more days after infection, with the first 5 days being the most accurate and dropping off after 8 days. False negatives are more concerning than false positives. If you get a false positive you can always retest, while a false negative would give someone a sense that they are free from disease which in the case of a false negative they would not be and could continue spreading the disease. When deciding on this test you must realize that it is the most accurate of all the current tests. There are antibody tests available as well, and while you get a faster result, they are less accurate and there have been reports of counterfeit antibody tests due to deregulation.
Barry Young 👏👏👏 YES SIR YES. Perfectly said. The primers are so meticulously crafted that they feel like a whole project in themselves. Love it though.
@@jpcapobianco1979 The antibody test is a blood test. I am not sure why you wouldn't be able to take it in your region. As I stated before there were/are issues pertaining to the antibody test, but it should be an option along side the PCR test. Keep in mind however, in any outbreak a PCR test will always be available before an antibody test. There are many reasons for this but the main one is that PCR is how the virus is identified in the first place. The antibody test is developed after the virus is identified and must go through many steps before it can be approved. Also, the antibody test doesn't test for the presence of the virus; it tests for the body's reaction to virus. So you may be positive for antibodies but be negative for the virus (false positive, you had virus but no longer have it), and vice versa (false negative, you have the virus but your body hasn't presented an immune response). This fact in itself has many issues that affects the reliability of the antibody test. The benefit as I mentioned before is that the results from the antibody test are very quick compared to those from the PCR test.
uncoverdc.com/2020/04/07/was-the-covid-19-test-meant-to-detect-a-virus/ “The first thing to know is that the test is not binary,” he said. “In fact, I don’t think there are any tests for infectious disease that are positive or negative.” The next part of his explanation is lengthy and detailed, but let’s push through: “What they do is they take some kind of a continuum and they arbitrarily say this point is the difference between positive and negative.” “Wow,” I said. “That’s so important. I think people envision it as one of two things: Positive or negative, like a pregnancy test. You “have it” or you don’t.” “PCR is really a manufacturing technique,” Crowe explained. “You start with one molecule. You start with a small amount of DNA and on each cycle the amount doubles, which doesn’t sound like that much, but if you, if you double 30 times, you get approximately a billion times more material than you started with. So as a manufacturing technique, it’s great. What they do is they attach a fluorescent molecule to the RNA as they produce it. You shine a light at one wavelength, and you get a response, you get light sent back at a different wavelength. So, they measure the amount of light that comes back and that’s their surrogate for how much DNA there is. I’m using the word DNA. There’s a step in RT- PCR test which is where you convert the RNA to DNA. So, the PCR test is actually not using the viral RNA. It’s using DNA, but it’s like the complimentary RNA. So logically it’s the same thing, but it can be confusing. Like why am I suddenly talking about DNA? Basically, there’s a certain number of cycles.” This is where it gets wild. “In one paper,” Crowe says, “I found 37 cycles. If you didn’t get enough fluorescence by 37 cycles, you are considered negative. In another, paper, the cutoff was 36. Thirty-seven to 40 were considered “indeterminate.” And if you got in that range, then you did more testing. I’ve only seen two papers that described what the limit was. So, it’s quite possible that different hospitals, different States, Canada versus the US, Italy versus France are all using different cutoff sensitivity standards of the Covid test. So, if you cut off at 20, everybody would be negative. If you cut off a 50, you might have everybody positive.”
@@danstoneman4353 yes,even everybody have in their body bad n good virus,so by our immune power it will be normal after some days, nowadays they started as business in hospital.
Your doctor was probably referring to the backlog. The hospital or the laboratory it uses has a fixed number of machines which can run a fixed number of samples at one time.
if you claim to be knowledgeable ...... is this a real quotation or not? “Quantitative PCR is an oxymoron.” Kary Mullis, inventor of PCR. As if it is then almost all the stats we have about Covid are bunk.
@@srilaasyakalidindi4798 PCR is a method to multiply DNA, Is not meant to detect sickness nor can it detect a virus. WHen making the PCR test, they did not have the gene code of Sars Cov2 virus, nor they have the Sars Cov2 virus. The test was made using data of other types of virus, So it is not worthy.
I don't really believe rt pcr. I was test antigen and rtpcr in the same day. I was negative in my antigen and positive in my rt pcr. But for me .its all about MONEY
Which Reagen you use . that's fake imperialism of the western type.but I have studied 10yera of medical sciences in Kiev Ukraine and I more believe their test.
How Convenient the inventor of the testing process died just before the outbreak was announced. What you and many others fail to understand and this example avoids telling you is that KaryMullins the inventor specifically said that the PCR testing is not meant for nor reliable for diagnosing any specific disease. There are actual diagnostics for that. Many are running the cycles so many times, especially beyond 10 until it will give you a positive test result.