Tuesday/ COVID-19 testing 101

I entered my address into the new Washington State COVID-19 test kit page on Friday.
Just yesterday, two 2-pack test kits landed on my porch.

The manufacturer’s website says these test kits correctly identify positive specimens in 94% of tests, and negative specimens in 98% of tests.

The test kits are for doing a so-called lateral flow test for COVID-19 antigens (proteins from the virus).

Doing the test seems pretty straight forward.
The test strip looks the same as the strip in a pregnancy test kit.
C stands for ‘Control’ and T for ‘Test’.

If both lines are colored (the T line may be very faint), the test is positive.
If only the C line is colored, the test is negative.
(If no line is colored, you did something wrong and the test is invalid.)

Here’s a table that I compiled of the types of COVID tests.

Polymerase Chain Reaction (PCR) ('Molecular')AntigenAntibody
Detects genetic material from the virus.Detects proteins from the virus. Detects immune system antibodies (a spike protein test or a nucleocapsid test).
The gold standard to test for an active COVID-19 infection.Not as sensitive as PCR tests.Not suitable to diagnose an active COVID-19 infection.
Nasal swab sample processed by a lab.Nasal swab sample processed by lab or with home test kit.Blood sample processed by lab.


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