How Do The Tests Work?
PCR Swab Test
This test is a swab of the back of the mouth (tonsils and pharynx) and the nose. It is most accurate when done by another person—preferably a healthcare professional. You can have this done at any of our many conveniently located London Medical Laboratory sites near you.
Having your swab sample done in-store ensures the lowest chance of a false negative result and the fastest turnaround times. However, you can also take your sample yourself by following the instructions included with your kit.
Your sample is analysed using the latest PCR technology in conjunction with our partner laboratories. It is a molecular assay based on the detection of the viral nucleic material (RNA) within the covid-19 coronavirus.
You should receive your result by late in the evening of the day after you have your swab delivered to our laboratory. This result will confirm whether or not there has been any virus detected on your swab. Though this turnaround time is delivered 97% of the time, this is a sensitive test that relies on a quality sample and therefore, there is always a small chance that your sample may require a rerun.
If your result comes back with ‘detected’ then you can be very sure that you have coronavirus in your nose or throat. The implications of this, whether you feel ill or not, is that you may be able to spread the virus and you should check the latest NHS advice here https://www.nhs.uk/conditions/coronavirus-covid-19/. This is particularly the case if you feel unwell or short of breath at all in which case you should visit https://111.nhs.uk/service/COVID-19/ where you will find out more information on what to do next.
If you receive a ‘not-detected' result, then it is cautiously good news. But this does not completely guarantee that you have not been exposed to COVID-19 as it has only tested your sample on the swab. There is between 70%-95% sensitivity rate with getting the virus on the swab depending on the swabbing technique. This means that there is up to a 30% chance that you did not get swabbed effectively enough – so if you do begin to feel any of the symptoms of coronavirus then please seek help.
It is worth noting that the PCR test is not the best test for checking whether you are infectious or not. The PCR test can detect fragments of viral DNA some weeks after your levels have dropped below the amounts of virus that are needed to be infectious to others. A better way to quickly check if someone you are infectious is with the Rapid Antigen Test.
Rapid Antigen Test - Results in 15 minutes
These tests detect viral protein fragments and return results within 15 minutes.
This test is ideal for quickly checking whether you are infectious and at risk of spreading the virus. The test is ideal for workplaces, film sets and any other situations where it is important to regularly check whether people are going to be spreading the virus to anyone else.
Rapid Antigen Results
This is an on-site test only and your results will be given to you at the time of testing—within 15-20 minutes—and a certificate will be sent to you via email soon after.
The Abbott Panbio Antigen Rapid Test that we use has shown a 98.2% sensitivity in detecting viral levels that are currently considered to be infectious (Ct values < 33). It has an overall sensitivity and specificity agreement with RT-PCR results of 97.9%. It has a reported specificity of 99.4%.
A positive result has a very high chance of confirming if you are carrying covid-19 virus in enough quantities to make you infectious. A negative result gives a very high likelihood that you are not infectious. Regular testing is recommended to ensure that this remains the case every time you intend to be in close contact with anyone.
IgG Antibody Test
This tests your blood for the presence of antibodies that your body has produced in response to being exposed to the virus. This new breakthrough in coronavirus antibody testing is used by the NHS and is PHE evaluated, FDA EUA approved and CE marked.
You will get your results within a day of your blood sample being received by our laboratory. Your result will let you know whether IgG antibodies have been detected or not.
This test has been shown to be between 96% and 100% sensitive in identifying antibodies to SARS-CoV-2 coronavirus at 14 days after onset of covid-19 symptoms. It is also 99.63% specific, which means that only a fraction of those tested who could not have been exposed to SARS-CoV-2 showed a false positive result.
The IgG test is PHE approved, CE marked, FDA EUA approved and is used globally to track exposure to coronavirus.
Please note, research into the effectiveness of coronavirus antibodies is still new and ongoing, so having antibodies does not mean you have immunity. Also, it is not yet clear how long immunity lasts, even if there is any. So please do continue to follow government guidelines regarding coronavirus if you are confirmed to have antibodies.
IgG Quantitative Antibody Test
This brand-new CE marked test works to evaluate your immune status by providing a quantitative measurement of IgG antibodies in your system.
This test is best taken at least seven days after your initial coronavirus infection or vaccination. This is because levels are likely are to continue to rise up to 15 days, at which point the test is 99.4% sensitive in confirming your exposure to the spike protein of the virus.
If you receive a positive result from this test, this is because the test detected an AU/ml level above 50 (on a full scale 0-8,000AU/ml). This is the minimum threshold where it can be presumed that you have been either been exposed to coronavirus or that your body has produced an immune response to your vaccination
It is not yet known how long antibodies last or how effective coronavirus antibodies are against the virus, as research into this is ongoing. There is evidence that a person’s immune response to infection drops off significantly over 6-9 months, however, it is unknown how high your IgG levels remain after vaccination.
Private Coronavirus Tests and the NHS
The NHS has been crucial in stepping up to provide coronavirus testing and treatment during this challenging time. So, our goal has been to assist in the national effort to ensure that everyone can get the testing they need.
The NHS currently only offers to test those who present symptoms and advises travellers to get tested through a private provider, so this is where we stepped in. We extended our traditional phlebotomy diagnostic services to cover PCR, antigen and antibody coronavirus testing—using the latest technology available.
While some clinics offer results in up to 72 hours, we have optimised our testing and handling process so you can get a PCR test as soon as the same day after we receive your sample.