As mentioned in the instructions, there are two tests that are being used to test for COVID-19. The two types of tests include a molecular or serological test according to Medical News Today. The molecular test involves taking a swab from the back of the throat. After this, the content is examined for the virus’s RNA genetic material. This test cannot test for past infections.
The serological test looks for antibodies in the blood. This test looks for IgM and IgG (Medical Net). If IgM titters are the only antibodies in the blood then it means that the person was barely infected by the virus. This means that B cells have yet not been fully activated to have a more specific antibodies made. If both IgG is and IgM titters are present then it could be the person is in the middle stage of the virus where the cells are class switching from IgMs to IgGs. If only IgGs are present then it could mean that the person was infected or is at the last stages of the virus. The virus could still be spread if the virus is still present.
After reading both of the articles, I think using either test could produce some erroneous testing results. By using a molecular test, a false negative could be acquired. It could be possible that the swabbed sample just did not have the virus. In the use of a blood test, I think a false positive can be obtained if the individual has been exposed to other COVID strain. Though these tests are not 100% accurate, I am glad that there are some tests available that we can rely on.
Vanessa's Mircrobiology Blog 