Blood Test

Antibody or PCR Test

Offering the right test for you

The Difference Between Antibody (IgG/IgM) Tests and PCR Tests

Last Reviewed: 3rd May 2020

Do you want to check if the fever or illness you had over 14 days ago was Covid-19?

You require the Antibody Test

Do you think you currently have Covid-19 symptoms?

Have you been exposed do the virus and need to know if you should isolate for 14 days?

You require the PCR Home-Kit Test

PCR Tests

This tests for presence of the virus on swabs. It does not test blood.

A PCR test looks for the presence of the RNA of the virus itself. This means that it will pick up the presence of the actual virus in the nose and throat. It is 100% accurate and will be able to confirm whether anyone with symptoms has the virus. It will also pick up whether the virus is present for people who have been exposed but are not showing any symptoms as yet. So long as there are viruses present on the swab the laboratory receives it will be reported "virus detected".

NB: This test only picks up whether there is virus on the swab that is delivered to the laboratory. If you have recovered and the virus has been cleared from the body, or the swab is not taken carefully and thoroughly as per the instructions, there may not be any virus on the swab in which case the test will be reported as "virus not detected".

IgG Antibody Tests

This tests your blood for the presence of antibodies that your body has produced in response to being exposed to the virus. It is only very recently that reliable tests for the presence of antibodies have been made available here. The gold standard so far is the PHE approved, FDA EUA approved reagents we use, millions of which are being shipped to the NHS here, to Europe and the world to be used in the frontline of detecting the spread of SARS-Cov-2 coronavirus through our communities.


There is however still a great deal to learn about this virus. Despite the accuracy of the test there is still much to learn about what is safe behaviour after finding out your result. It is most definitely not recommended that anyone assumes they have immunity and can go about life as what used to be normal before this pandemic just because there are antibodies in their blood.


The test has so far been shown by the FDA to be 100% sensitive in detecting antibodies 14 days after the first symptoms of confirmed SARS-CoV-2 infection* but it is not yet known whether antibodies definitely do give immunity and if they do, for how long. 

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Enquiries@claretdiagnostics.com

0333 577 0939

Unit 6 Minerva Bus Centre, 58-60 Minerva Road, Park Royal, London, NW10 6HJ

Claret Diagnostics is a branch of London Medical Laboratory. London Medical Laboratory are regulated by the Care Quality Commission. Certificate number: CRT1-4708702735