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Types of COVID-19 Tests

Close up of young woman with sample swab. Selective focus on sample. Corona virus protective measures.
by: Felicia Wickett
June 3, 2023

COVID-19 testing plays a crucial role in identifying and managing the spread of the virus. With various testing options available, it’s essential to understand the different types of COVID-19 tests and their characteristics.

In this comprehensive guide, we will explore different kinds of tests and look into their specificities.

COVID test types: What are the different types of COVID-19 tests?

The types of COVID-19 tests available vary depending on your country and healthcare provider.

Depending on your condition, it‘s also essential to discuss with your healthcare provider which test is best for you.

  1. Polymerase chain reaction test: The PCR test is one of the nucleic acid amplification tests widely regarded as the gold standard for diagnosing COVID-19. It detects the genetic material (RNA) of the SARS-CoV-2 virus. This test is highly sensitive and specific, which can detect even low levels of viral RNA. It plays a crucial role in identifying individuals with current infections.
  2. Antigen test: This rapid diagnostic test is designed to detect specific proteins (antigens) on the surface of the SARS-CoV-2 virus. Antigen tests are relatively quick and provide results within minutes, making them valuable for immediate decision-making, such as screening large populations or diagnosing acute infections.
  3. Antibody test: Antibody tests, also known as serology tests, detect the presence of antibodies produced by the immune system in response to a previous SARS-CoV-2 infection. These tests are valuable in determining past infections and studying population immunity. This is one of the COVID test types that involve blood samples.
  4. Saliva test: Saliva tests are a non-invasive alternative to traditional swab-based tests. These tests involve collecting a saliva sample from the individual and analyzing it for the presence of the SARS-CoV-2 virus.
  5. Nasal swab test: Nasal swab tests are relatively simple to administer and provide a good sample for detecting the virus. They have been extensively used in diagnostic settings and are essential in identifying current infections.

Molecular tests for COVID-19

These are diagnostic tests that detect the presence of the virus that causes COVID-19. Molecular tests typically use polymerase chain reaction to check a sample of a person’s respiratory secretions, such as a nose or throat swab, for the presence of the virus.

PCR tests are the most reliable type of COVID-19 test available and are used to diagnose active infections. They’re considered the “gold standard” for COVID-19 testing and are used for both diagnostic and surveillance purposes.

How is the test done?

Sample collection: A trained healthcare provider will collect a respiratory sample from the patient, usually through a nasal or throat swab. In some cases, samples can also be collected from saliva or other respiratory secretions.

Sample processing and testing: This part involves technical processes conducted by trained professionals. The process includes:

  • RNA extraction
  • Reverse transcription
  • Amplification
  • Detection

Result interpretation: The presence of amplified viral genetic material indicates a positive result, suggesting an active COVID-19 infection. If no viral genetic material is detected, the result is considered negative for the SARS-CoV-2 virus.

When can I expect my results?

PCR test results take a few hours to a few days, depending on the testing capacity and laboratory turnaround time.

How accurate is this test?

PCR tests are considered the most reliable and accurate test for detecting active infection, with a low rate of false negatives. They have high sensitivity in detecting the virus’s genetic material, even in individuals with low viral loads.

How much does it cost?

The cost of PCR testing can vary depending on various factors, such as the:

  • Testing location
  • Healthcare provider
  • Insurance coverage

According to several sources, the price of a PCR test starts at $100.

It’s advisable to check with your healthcare provider or local health authorities for specific cost details.

Antigen tests for COVID-19

Antigen tests are rapid diagnostic tests, often just called rapid tests, that detect specific proteins from the SARS-CoV-2 virus. These tests are designed to provide quick results, making them useful for mass testing and screening purposes.

How is the test done?

Sample collection: A healthcare professional collects a respiratory sample, usually using a nasal or throat swab, from the individual being tested.

Sample processing: The collected sample is mixed with a testing solution containing specific antibodies that can bind to SARS-CoV-2 antigens if present.

Antigen-antibody reaction: If the SARS-CoV-2 virus is present in the sample, a visible reaction occurs between the viral antigens and the antibodies in the testing solution.

Result interpretation: A positive test result is indicated by the appearance of a visible reaction, often shown as a color change or line formation on a test strip or device. This suggests the presence of viral antigens and indicates an active COVID-19 infection. A negative antigen test result indicates the absence of viral antigens in the sample.

Blurred nurse in medical mask taking samples for coronavirus test from young man

When can I expect my results?

Antigen tests provide results within 15 to 30 minutes, making them suitable for rapid testing and immediate decision-making.

How accurate is this test?

Antigen tests have a slightly higher chance of false negatives compared to PCR tests. While they offer quick results, there’s a higher likelihood of missing an infection in individuals with low viral loads, especially in ones that don’t show symptoms.

However, they are generally effective in identifying individuals with high viral loads and those who are most likely to spread the virus. Moreover, most reliable tests offer higher accuracy rates nowadays.

How much does it cost?

Antigen tests are generally more affordable than PCR tests.

Like PCR tests, the cost can vary depending on the:

  • Testing location
  • Healthcare provider
  • Insurance coverage

For more specific details, inquire about the cost from your healthcare provider or testing facility.

At-home tests are often more affordable than ones done in a testing center. Self-tests usually cost around $20 to $60, depending on the brand you purchase. Some kits also include multiple tests, which are more economical.

Antibody tests for COVID-19

Antibody tests, also known as serology tests, detect the presence of antibodies produced by the immune system in response to a SARS-CoV-2 infection. These tests help identify individuals who have previously been infected with the virus.

How is the test done?

Sample collection: A healthcare provider collects a blood sample, usually through a finger stick or venipuncture, from the individual being tested.

Sample processing: The collected test sample is processed to separate the serum or plasma containing antibodies from other blood components.

Antibody detection: The serum or plasma is analyzed to detect the presence of antibodies specific to the SARS-CoV-2 virus. This can be done using various techniques such as:

  • Enzyme-linked immunosorbent assay (ELISA)
  • Lateral flow immunoassay
  • Chemiluminescent immunoassay

Result interpretation: Specific antibodies indicate a positive result, suggesting that the individual has been exposed to the virus and has developed an immune response. The absence of detectable antibodies may indicate no prior infection or that antibodies have not yet developed in the early stages of infection.

When can I expect my results?

Results for antibody tests are usually available within a few hours to a few days, depending on the testing facility and laboratory processing time.

How accurate is this test?

Antibody tests are reliable for identifying past infections and determining the presence of antibodies. However, it takes time for the body to develop detectable antibodies after infection, so antibody tests may not be effective during the early stages of infection.

How much does it cost?

Like other kinds of tests, antibody testing costs vary depending on different factors, but usually starts at $50.

What type of test should I get?

Determining the type of COVID-19 test you should get depends on various factors, including your specific circumstances, symptoms (if any) and the purpose of the test. Here are some general guidelines.

  • Diagnostic testing: If you’re experiencing symptoms of COVID-19, such as fever, cough, difficulty breathing, loss of taste or smell or other flu-like symptoms, it’s recommended to undergo a PCR test as it can confirm an active infection.
  • Past infection assessment: If you suspect that you may have had COVID-19 in the past and want to determine if you have developed antibodies against the virus, an antibody test (serology test) is appropriate. These tests can help identify individuals who have been previously infected and have developed an immune response to the virus.
  • Screening and surveillance: An antigen test may be suitable for screening purposes or in situations where rapid results are needed. These tests provide quick results and can be useful in identifying individuals with high viral loads who are more likely to be contagious.

It’s crucial to consult with a healthcare professional or follow the guidance of local health authorities when deciding on the type of test to get.

Key takeaway

COVID-19 tests are tools for detection and diagnosis, but they should always be used in conjunction with other preventive measures, such as practicing good hygiene, maintaining physical distance and following public health guidelines to reduce the spread of the virus.

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