COVID-19 Test Frequently Asked Questions
COVID-19 tests are used to detect whether the patient is currently or previously infected with the SARS-CoV-2 virus by methods such as PCR tests, antibody tests, antigen tests, and chest CT tomography.
COVID-19 Antigen Tests
COVID-19 Antibody Tests
COVID-19 PCR Tests
Should I use COVID-19 PCR Tests if I have already used the COVID-19 Antigen Test?
COVID-19 PCR Tests are needed if the COVID-19 antigen test indicates a positive result.
If the COVID-19 antigen test indicates a negative result, but the patient has been recently exposed to a high-risk environment or population, it is recommended to conduct a COVID-19 PCR test to confirm the status of infection.
The Difference between PCR, Antigen, and Antibody Tests
| PCR Tests | Antigen Tests | Antibody Tests |
Concept | SARS-CoV-2 has genetic material in the form of RNA. Presence of COVID-19 specific viral RNA from patient samples indicate that the patient is SARS-CoV-2 infected. | Antigens are present on the surface of the virus. Presence of COVID-19-specific antigen in patient samples indicate that the patient is SARS-CoV-2 infected. | Production of antibodies are triggered after COVID-19 infection. Status of infection can be confirmed by detecting the presence of IgM or IgG antibodies in patient blood samples. |
Testing Principle | PCR tests amplify and detect targeted region of SARS-CoV-2 genetic material. | Antigen tests detect SARS-CoV-2 antigen in patient samples. | Antibody tests detect IgM and IgG antibodies targeting SARS-CoV-2 in patient samples. |
Sample Type | Nasal, nasopharyngeal swab, oropharyngeal swab, deep throat saliva | Nasal, nasopharyngeal swab, oropharyngeal swab | Blood (Whole blood, plasma, serum) |
Biomarker | SARS-CoV-2 virus | SARS-CoV-2 antigen | SARS-CoV-2 IgM and IgG antibodies |
Suitable period for use | From onset of infection | From 2 days after infection | From 7 days after infection |
Operation Time | 4-6 hours | Around 20 minutes | Around 20 minutes |
Operation Requirements | Professional medical operator and lab equipment | No professional operator or equipment required | No professional operator or equipment required |