A test to find out whether people have been infected with coronavirus in the past has been approved by health officials and could be rolled out within weeks.
Here are the answers to some of the key questions about the new test:
What is the new test?
Pharmaceutical giant Roche has developed a test which can tell whether somebody has ever had coronavirus.
The test involves taking a small sample of blood and testing it for antibodies which will indicate exposure to Covid-19.
Public Health England (PHE) has evaluated the new Roche test and has approved it as being safe and reliable for widespread use.
How reliable is it?
The test picks up 100 per cent of people who have had coronavirus.
This means it has 100 per cent sensitivity - making it very reliable,
It also has a specificity of over 99.8 per cent, this means it picks up virtually all people who have not had the virus.
A test that is 100 per cent specific means all healthy individuals are correctly identified as healthy - so there are no false positives
What if I've never had any symptoms of Covid-19?
Whether you've had symptoms or not doesn’t matter.
Experts believe a proportion of people who have had Covid-19 never actually develop symptoms - they are aysmptomatic.
The new test can identify people who have had coronavirus even if they have never had any indication they had contracted it.
If the test shows I've had Covid-19, am I now immune from it?
Scientists are unsure as there is still a lot to learn about the new coronavirus.
Experts believe that while the presence of antibodies indicates a level of immunity, it is unclear whether people are completely protected and how long immunity - if any - lasts.
There has been some suggestion that immunity could last for two to three years but more work needs to be done.
Can I get the new test?
The Government plans roll out the test to front-line workers first, such as those in health and social care.
Number 10 said the new antibody test would "certainly" be available on the NHS, but said commercial discussions with Roche are ongoing.
It is hoped the test will become available to the wider public - although it is unclear whether this will be via the NHS or through commercial websites.
Roche says it will be able to provide hundreds of thousands of antibody tests to the UK every single week.
Coronavirus: Everything you need to know