Greater than CT28 and its a complete waste of time
Fauci says so
The NYT says so
MIT says so
But as we learn more, this binary way of viewing test results — positive/negative, infected/not infected — may change. After all, the amount of virus in a sample is directly correlated with the number of amplification cycles needed to detect it, a number known as its cycle threshold (Ct). A positive test that comes back positive in 20 cycles contains a greater amount of virus than one requiring 40 cycles. Right now, we just call both results “positive.” But it’s obvious that the first sample came from an individual with a higher viral load. And the greater the viral load, the more contagious the patient is likely to be.
Portuguese courts say so
The goddamned inventor of the tests says so
STOP SAYING "BELIEVE THE SCIENCE" and start UNDERSTANDING THE GODDAMNED SCIENCE you absolute numpties.
Strange how the CDC said to use 40.. in their previous declarations
All clinical samples should exhibit fluorescence growth curves in the RNase P reaction that cross the threshold line within 40.00 cycles (< 40.00 Ct), thus indicating the presence of the human RNase P gene. Failure to detect RNase P in any clinical specimens may indicate:
- Improper extraction of nucleic acid from clinical materials resulting in loss of RNA and/or RNA degradation.
− Absence of sufficient human cellular material due to poor collection or loss of specimen integrity.
− Improper assay set up and execution. − Reagent or equipment malfunction.
And if at 40 (the absolute max possible of the machine) and you find nothing, report it as invalid (not negative).. COME ON PEOPLE.