A new "no swab" saliva coronavirus test that lets people collect their own sample at home by spitting into a pot is being trialled in the UK.
More than 14,000 GP staff and other key workers, along with the people they live with, will take part.
The pilot, led by Southampton University, will run for four weeks.
Experts hope a saliva test will be an easier option for people - swabs can be uncomfortable and need to go deep into the nose and throat.
The tests are designed to identify if a person is currently infected with coronavirus.
Participants in the trial, which will include some university staff and students, will provide weekly saliva samples for lab testing.
The kit will be delivered to their home or workplace and then collected by staff working for the trial team or returned to an agreed location.
It could potentially spot people who are infected but have no symptoms, yet still risk passing the disease on to others.
The trial is in addition to routine coronavirus testing already being offered to NHS staff and any people with symptoms.
Health Secretary Matt Hancock said he was grateful to everyone involved in the trial: "Saliva testing could potentially make it easier for people to take coronavirus tests at home, without having to use swabs. This trial will also help us learn if routine, at-home testing could pick up cases of the virus earlier."
Anyone who tests positive for the virus will be asked to self-isolate to avoid spreading the infection.
The saliva test looks for genetic material of the virus using a technique known as loop-mediated isothermal amplification (LAMP).
Experts say this can be simpler and faster to carry out than the standard polymerase chain reaction (PCR) testing method used to analyse coronavirus swabs.
Ultimately, it might be possible to do the testing as well as the sampling at home and get results in under an hour.
As well as trialling the Optigene saliva test, the Southampton team are exploring the use of other no-swab saliva-based coronavirus tests with companies including Chronomics, Avacta, MAP Science and Oxford Nanoimaging.