What is the difference between Covid PCR, Antigen and Antibody Tests

Dr Joachim Stolte

Published: 04/02/21

There are a number of tests for Coronavirus (Covid-19) available on the market and it can be a bit confusing when you are deciding which is the right one for you. 

We’ve made it easy for you to decide by summarising the different tests that Rapid Health Test provide to help you make the right decision.

Firstly it might help to understand some of the terminology we use when we talk about the makeup of the Coronavirus (Covid-19):

RNA: The genetic code which makes up the core of the virus

Envelope Protein: The protective coat which surrounds the RNA.

Spike Protein: The characteristic spikes which protrude from the envelope and attach themselves to human cells.

What is a Covid PCR Test?

A PCR (or polymerase chain reaction) Test will detect the presence of antigens in your body.  An antigen is a foreign invader (such as bacteria or a virus) and the PCR test is able to look specifically for Coronavirus (Covid-19) antigen.  The PCR test will find, isolate and collect the RNA (the genetic code of the virus) if you have the virus present in your body.  This will tell you whether or not you have Coronavirus (Covid 19).

These tests are considered the ‘gold standard’ and because of this, the Government has rolled out mass PCR testing facilities to try and find how widespread Coronavirus (Covid-19) is in the U.K.

The PCR test itself involves a gentle lower nasal and throat swab which can be done in our clinic by one of our health care experts, or in the comfort of your own home.  When the swab is done, the cotton bud is sealed in a container and sent to either our in-house laboratory or in some cases we will send these to an external laboratory. 

We offer private Covid PCR tests in the following circumstances:

  • Covid Fit to Travel Certificates – These can be done in clinic or at home
  • Covid Test to Release Certificates – These need to be done in clinic
  • Private Covid PCR tests – These can be done in clinic or at home

If you are doing a test at home, you will be given full instructions which we recommend you follow carefully.  When you require a Test to Release certificate, we will use an external laboratory because they will be able to identify if you are carrying one of the new variants of Coronavirus (Covid-19).

What is a Covid Lateral Flow Test?

In a similar way to the PCR Test, the Lateral Flow Test will detect the presence of the Coronavirus (Covid-19) antigen in your body.  However, instead of detecting the Coronavirus RNA, the lateral flow test will detect proteins which indicate if you are carrying the virus.

Once again, you’ll need a gentle lower nasal and throat swab.  The swab is then put into a buffer solution which is dropped onto a test device.  As the solution is drawn along the lateral device, rather like a pregnancy test, the result is revealed.

Because your swab doesn’t need to be sent to an external laboratory, the lateral flow test is very quick with results available in approximately 15 minutes.

How Accurate are Covid lateral flow tests?

The tests we provide are very accurate. We work with suppliers who provide test which are highly sensitive (this means they are reliable in terms of picking up positive results) and highly specific (this means that they are reliable in terms of identifying negative results).  This means that Rapid Health Test Lateral Flow tests are ideal for picking up cases of Coronavirus (Covid-19) in people who are asymptomatic or if you want to rule out infection when visiting relatives.

We offer private Covid lateral flow tests in the following circumstances

Covid Fit to Travel – These can be done in clinic or at home

Private Covid Lateral Flow Test – Perfect for workplace testing, or if you are visiting family.


What is the Covid Antibody Test?

You may have already had Coronavirus (Covid-19) or you may have been vaccinated and you want to know whether or not you are carrying Antibodies.

Antibodies are proteins that our bodies produce as a result of being exposed to antigens such as bacteria or viruses.  Antibodies are part of our immune system and attach themselves to antigens in order to remove them from our bodies. 

We don’t yet know how long antibodies to Coronavirus (Covid-19) last in our bodies which means that it is uncertain how long we will remain immune after being infected or vaccinated.

If you test positive, it is still possible that you could be re-infected, so you should continue to take precautions such as wearing masks and PPE if you are required to do so.

If you test negative, it is possible that your body hasn’t developed sufficient antibodies because you either have a current infection, or you’ve only been infected (or vaccinated) recently.

Our Antibody test is a simple Finger prick test which will take a drop of blood.  This is dropped onto a device along with a buffer solution.  In a similar way to the lateral flow test, your results will appear within approximately 15 minutes.

If you are travelling to China, you’re required to have a negative PCR test and an Antibody test before you enter the country.  We suggest you keep an eye on the Government website regarding travelling abroad as the situation is updated regularly.

We offer an Covid Antibody Test in the following circumstances

  • If you wish to know if you are currently immune to Coronavirus (Covid-19)
  • If you are planning to travel to China.

We only do Covid Antibody Tests in our Truro clinic and can provide you with a certificate depending on the results.

Who do we share your test results with?

If you order a PCR or Lateral Flow Test from us, we are obliged by law to report your results (positive, negative or void), along with your name to Public Health England.