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') | Antigen | Antibody |
|---|---|---|
| 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. |