Antigen and antibody tests may sound similar but they play very different roles in the fight against Covid-19. What are the differences?

Antigen or antibody test?

Covid-19 antigen tests are used to detect whether someone currently has coronavirus, while antibody tests can determine whether someone has Covid-specific antibodies to help their immune system fight off a future infection.

You might be asked to take an antigen test before attending an event or as a precautionary measure by your employer. You may also want to take one if you suspect that you have Covid-19 or you believe you may have been in contact with someone who has tested positive for the virus.

AlphaBiolabs offers a rapid and non-invasive antigen test for professional and business use, which uses a lateral flow device to produce an accurate result in just 15 minutes. The test can be carried out on-site in the workplace and you only need to take a sample from your nose using the swab provided.

If the result is positive, the lateral flow device will show two lines. If no Covid-19 antigens – proteins on the surface of a virus – are found in your sample, the result will be negative and just one line will be displayed.

Antigen tests are most effective when taken within 14 days of the onset of symptoms or potential exposure to the virus. They can however be taken at any time to monitor whether or not someone has an active infection, and regular testing can be carried out by employers as part of a workplace health initiative to minimise the risk of a Covid-19 outbreak.

What does an antibody test show?

Unlike an antigen test, a Covid-19 antibody test will not tell you whether you have coronavirus. The purpose of the antibody test is to determine whether your body has created Covid-specific antibodies designed to prevent or fight a future infection.

An antibody test can show you whether a Covid vaccine has been effective or, if you have previously had the virus, whether your body still has the antibodies produced as a result.

Some people use antibody tests for peace of mind. Others may have concerns about their immune system and may want the results of an antibody test so they can decide what precautions they need to take to protect themselves from an infection.

Unlike an antigen test which requires a nasal swab, antibody tests require a small sample of blood taken from a fingertip. When you order an antibody test from AlphaBiolabs, you will be sent a sample collection kit with simple instructions and a sterile lancet to help you obtain your sample.

With our advanced laboratory antibody and immunity test, your blood sample will be sent to our UK-based laboratory for analysis. Your testing kit will include a pre-paid envelope to post your sample back, and this will be securely tracked to ensure it does not go astray.

Once we have received your sample, we will send you your result report within three days via email. Your report will not only tell you whether any Covid-specific antibodies were found in your blood, it will also detail whether they were at a high, medium or low level.

AlphaBiolabs also offers rapid antibody tests for professional and business use. These use a lateral flow device and can be carried out on-site by adding a couple of drops of blood and a buffer solution onto the testing device.

The rapid antibody test will tell you within 10 minutes whether any antibodies were found. However, these tests cannot give any indication of the level of antibodies you have in your blood.

If you have any questions about the various Covid-19 testing services offered by AlphaBiolabs for the general public, for travel testing, or for the workplace, call our team today on 0333 600 1300 or email

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AlphaBiolabs offers a range of COVID-19 testing options for private individuals and businesses