Frontline NHS workers are being tested to see if they have coronavirus.
The roll-out of testing in England follows that in Wales, Scotland and Northern Ireland.
It is hoped that the number of people tested will increase rapidly in the coming weeks, but who can be tested at the moment?
Which NHS workers are being tested?
Critical care doctors and nurses are being tested first, followed by staff in emergency departments, paramedics and GPs.
Healthcare workers in England are being sent kits to their homes, with samples sent to one of three new labs. It’s part of a collaboration involving Amazon, the Royal Mail and Boots, as well as research labs and universities.
Cabinet Office minister Michael Gove said the tests – which will check whether people currently have the disease – would give health and social care workers “security in the knowledge that they are safe to return to work if their test is negative”.
The measures follow criticism from NHS staff over a lack of testing.
Who else gets tested for coronavirus?
Before the decision was made to test NHS staff, only seriously ill patients in hospital with flu-like symptoms were being routinely tested for the virus.
Currently, about 6,000 people are tested daily. But by the end of March it wants to test 10,000 people a day, rising to 25,000 by mid-April.
Is a new test being developed?
Scientists are also looking at tests which can check whether someone has had the disease in the past. These look for markers of immunity called antibodies in the blood.
They use a drop of blood on a device a bit like a pregnancy test.
This could help work out how widespread the disease has been and whether people are safe to go back to work
The government said it has bought three-and-a-half million of these tests and plans to make them available “very soon”, if they can be proved to work.
However, it will not be available immediately, according to the government’s chief medical officer, Prof Chris Whitty.
“I do not think – and I want to be clear – that this is something we’ll suddenly be ordering on the internet next week,” he said.
Can I buy a private test?
You can, but Public Health England advises against it, as it says there is not yet enough information about them.
“It is not known whether either a positive or negative result is reliable,” reads a statement on its website.
A private healthcare clinic in London defended its decision to charge £375 for a test.
Reports suggest other firms have also increased the price of their testing kits.
What is the UK doing?
In total, 104,866 people in the UK had been tested for coronavirus as of 26 March.
There are two main reasons for testing people – to diagnose them individually, and to try to understand the spread of the virus. This is called surveillance testing, but is not being done by the UK at present.
Not testing more widely means that many people might be self-isolating for no good reason, including NHS workers. Healthcare staff have also raised concerns that they could be spreading the infection unknowingly.
What do I need to know about the coronavirus?
Should the UK be testing more people?
The director general of the World Health Organization (WHO), Tedros Adhanom Ghebreyesus said he had a “simple message” for all countries: “Test, test, test.”
He added: “We cannot stop this pandemic if we do not know who is infected.”
The UK does not have the resources of equipment or staff to do mass testing at the moment, although the government is trying to increase its capacity.
It has done more testing than many other countries, although not more than the most rigorous testers like South Korea.
The UK passed its 2,500th case on 18 March and had tested 828 people per million of its population. At the same point in their outbreaks, Italy had conducted 386 tests per million citizens, while South Korea had done more than 2,000 tests per million.