2020-11-13

@MrSammy_H @max_roi @rossy65 This a great reference! Worth a read.

Case closed https://t.co/pUYiJcAdD6

Soon https://t.co/mWOpR7W8kk

@PPathole Fwiw, lab I just spoke to thinks below 30 is accurate, 30 to 40 gets dicey & above 40 is bs. Will talk to several more labs. There must be a graph of PCR amplification cycle vs false positive rate somewhere.

Lab I just spoke to said cov2 PCR detection (N1 & N3 genes) below 30 cycles is reliable & above 40 cycles is not

@RationalEtienne @ryaneshea Note, this is not the spike protein. They don’t consider that reliable.

@RationalEtienne @ryaneshea Just spoke directly to a testing lab. Their main PCR search is for the N1 gene, unique to cov2. N3 is also sought, but is generic to other sars viruses. High PCR cycle count *does* give false positives, but they believe accuracy is good below 30 cycles & 40 cycles is their max.

@PPathole Strange

@ryaneshea Possible explanation for the dramatic decline in cold & flu prevalence vs prior years. If someone comes in with cold/flu symptoms & falsely tests positive for cov2, they will assume they have it, when in fact they simply have some other form of seasonal cold/flu.

@ryaneshea Moreover, lower the true prevalence, the higher the false positive number will be. This sounds obvious, but it could mean a very high false positive percentage if true prevalence is low.

@ryaneshea From https://t.co/42z7vRPB9c https://t.co/XTSukcc3Tl

@dana_e_morgan Sure is

Would be great to hear from people who know a lot about the PCR testing industry. What’s the approximate false positive rate, all things considered, for cov2 PCR tests?

@ClareCraigPath Interesting

@john_beans @DirtyTesla Interesting

What is the general population (no knowledge of symptoms) accuracy of a sars-cov2 PCR test & is it possible to generate a false positive if you simply run enough cycles?

@PPathole @cleantechnica A good PCR test should identify if I have the cov2 spike proteins, although I have heard some low accuracy numbers for those too. Hard to get a straight answer. False positives will roughly scale with # of tests & daily test rate has gone ballistic: https://t.co/Pv6s71jZQo

@justpaulinelol @cleantechnica Mild sniffles & cough & slight fever past few days. Right now, no symptoms, although I did take NyQuil.

@cleantechnica Technically, I tested positive, then negative twice, then positive again, so “Elon Musk Tests Negative for Covid” is an equally correct title. The “rapid antigen test” from BD seems to be about as useful as a flipping a coin.

The carousel turns ever faster

@JoeInGeneral @andrewbogut Yup

@ajtourville Exactly

@JaneidyEve Symptoms of a typical cold. Nothing unusual so far.

@BLKMDL3 If it’s happening to me, it’s happening to others. I’m getting PCR tests from separate labs. Results will take about 24 hours.

Something extremely bogus is going on. Was tested for covid four times today. Two tests came back negative, two came back positive. Same machine, same test, same nurse. Rapid antigen test from BD.

@austinbarnard45 Burst disk worked, so vehicle appears to be ok. We’ll have to swap out at least one of the engines.

@tobyliiiiiiiiii @SpacePadreIsle @austinbarnard45 Maybe melted an engine preburner or fuel hot gas manifold. Whatever it is caused pneumatics loss. We need to design out this problem.

@austinbarnard45 We lost vehicle pneumatics. Reason unknown at present. Liquid oxygen header tank pressure is rising. Hopefully triggers burst disk to relieve pressure, otherwise it’s going to pop the cork.