published on
March 11, 2022

PCR vs lateral flow Covid-19 testing: what's the difference?

Fiona Millington
posted on
COVID-19: Nurses & Carers

Florence Flex enables you to add the date of your last Covid-19 test to your profile.

This gives care home managers reassurance of your current test status when booking you in for vacant shifts. 

Here, we explain the difference in testing processes for PCR testing and lateral flow testing, including concerns around 90 day exclusion for those who have had a positive PCR test and are now recovering from Covid-19. 

What is the PCR test?

The PCR (polymerase chain reaction) test detects the presence of RNA, which is the genetic material produced by the virus to replicate within the human body.

The test involves taking a swab of mucus or saliva from the throat or nose and examining it for the presence of the virus’s genetic material.

A positive test result means that you are likely to have had Covid-19 at the time of the test. Whereas, a negative result means that you are unlikely to have had Covid-19 at the time of the test. You will usually receive your test results within 24 hours.

What is the lateral flow test?

The lateral flow test involves taking a sample of mucus or saliva from the nose or throat and mixing it with a solution that will break down the virus.  

The solution is placed on an absorbent strip which identifies the presence of antigens within the solution. These antigens are produced in response to the presence of the Covid-19 virus.

The lateral flow test is useful in detecting the virus in individuals who are asymptomatic or who have no symptoms of the disease.

A positive test result means that you are likely to have Covid-19 at the time of the test. Whereas, a negative test result means that you are unlikely to have Covid-19. Lateral flow test results are usually available within 10 - 30 minutes.

Exemption from routine testing

A PCR test is a swab that can either be taken at a testing site or at the care setting you are working at. Once the swab test has been sent off for examination, you will then have to await at least 24 hours for your results. 

If you have had a positive PCR test and have completed your isolation period, it is now recognised that you may continue to test positive for up to 90 days after the first test result.

You should not have either a PCR or lateral flow test within the first 90 days of a positive PCR test. 

Florence test question

When our Covid test question pops up when you log in to Florence, you can now select ‘no’ if you have had a PCR test already within the last 90 days.

It looks like this:

Florence covid test question

This means you can continue booking shifts with Florence in your 90 day exclusion period.

Retain your PCR test results

You should be prepared to demonstrate that you are within the 90 exclusion period if asked, so it is important to retain your test results until that time has passed. You can do this by taking a photo of your result, saving or printing your confirmation email and keeping it with you when you go to work.  

Please remember, if you develop new symptoms of Covid-19 within that 90 day timescale, you will need to have a new PCR test and isolate for 10 days.

For further information, please visit the Government website here

Here to help

We’re always here to provide the latest guidance and help you find work in your area - if you have any questions at all, please get in touch. Simply speak to your account manager directly, call us on 020 3911 2555 or email, and we’ll do our best to help you.

You may also be interested in:

Keep reading