How do antibody tests work?
Antibody testing looks for proteins in the blood, called antibodies, which are left over after your body fights off a disease.
When your immune system detects a new infection, your body starts producing antibodies, which it then trains to fight that specific invader. These antibodies figure out the invader's weaknesses, then neutralize, destroy and ultimately remove it from your body.
Antibody test kits contain proteins from the virus that antibodies bind to if they are present in a blood sample.
There are two types of antibody test, but they work on the same principle.
- The most reliable ones are lab-based tests called enzyme-linked immunosorbent assays or Elisas.
- The others are like pregnancy tests and can be used at home.
Both contain proteins from the virus that antibodies bind to if they are present in a blood sample.
The presence, and sometimes even the amount of antibodies, are detected by a colour change in the Elisa and the appearance of a line on the home test stick.
COVID-19 animation: Coronavirus and antibody testing explained
There are two kinds of tests for viruses like COVID-19. One tests for the presence of the virus in the sample, and the other for antibodies to the virus. Both are important for understanding who is infected and might transmit the virus to others, who have had the virus and might now be immune, and even who might potentially help others with treatment.
How Does Coronavirus Antibody Testing Work?
Stanford Health Care gave us exclusive access to show how coronavirus antibody testing works. So we followed two caregivers and their blood, through the testing process.