What is the difference between a PCR test and a lateral flow test?

UK government to announce overhaul in testing rules ‘in the coming days’

PCR tests will be replaced by lateral flow tests for travellers entering England in the coming weeks, cutting the cost significantly.

The UK Transport Secretary Grant Shapps said authorities are working with testing manufacturers to make sure there will be enough lateral flow kits on the market before any change is announced.

On Friday he said an announcement on a shift away from mandatory PCRs would be given "in the coming days”.

He said ministers hoped to have the new system in place in time for the half-term school holidays at the end of the month.

It is not yet clear if the devolved administrations in Scotland, Wales and Northern Ireland will adopt similar measures but they have mirrored recent changes made to England’s red list.

So what is the difference between the two tests?

Price tag

PCR – or polymerise chain reaction – tests cost about £65 ($88) and in-store ones retail for about £85. Private clinics tend to charge about £200 per test.

These prices are significantly higher than for lateral flow tests which can be sold for anywhere between £5 and £30.

If PCR tests were scrapped in favour of lateral flow tests it could save families hundreds of pounds per trip.

Taking the test

Both require a swab to be taken from the nose and throat, although some lateral flow test providers say a sample from the nose will suffice.

For a PCR, the swab has to be sent to a laboratory where researchers analyse it and the result is delivered to the customer, usually be email.

This can take up to two or three days, depending on the speed of the mail and if there are any backlogs in labs.

The LFT swab on the other hand is inserted into a capsule of liquid before being poured into a device at home.

Advice varies but most manufacturers say to wait about 15 minutes before accepting the results displayed.

Test results

PCR test results are sequenced in labs to pick up variants of concern. This is why they are recommended for people experiencing Covid symptoms.

Because of their high reliability in this regard, the government has so far been reluctant to replace them with LFTs.

However, the UK government has said that the quality of lateral flow tests has improved since the start of the pandemic.

Mr Shapps said “the sensitivity and specificity has improved on those tests” as he promised a change from PCRs in the near future.

On Thursday the UK parliamentary transport select committee urged ministers to offer clarity for people intending to travel to or from England in the coming weeks.

"Passengers and the travel industry need urgent clarity or it will be too late for those who need financial certainty to book the October half-term holiday,” they said.

Travel bosses have long said that pricey PCR tests are deterring people from booking flights abroad.

Updated: October 8th 2021, 2:20 PM