Health Secretary Matt Hancock was joined for the briefing by Prof Stephen Powis, Medical Director, NHS England and Prof John Newton, coordinator of the UK coronavirus testing programme.
Mr Hancock confirmed that Government had met its target to carry out 100,000 coronavirus tests a day by the end of April and said that testing would help "unlock" the lockdown.
Here’s what we learned from the daily briefing:
Government hits target of 100,000 coronavirus tests per day
The Government had met its target to carry out 100,000 coronavirus tests a day by the end of April after 122,347 tests were performed in the 24 hours up to 9am on Friday.
Speaking at the daily Downing Street press briefing, Mr Hancock said: "I knew that it was an audacious goal, but we needed an audacious goal, because testing is so important for getting Britain back on her feet.
"I can announce that we have met our goal. The number of tests yesterday, on the last day of April, was 122,347.
"This unprecedented expansion in British testing capability is an incredible achievement, but it is not my achievement, it is a national achievement."
Testing is 'crucial to suppressing the virus'
The Health Secretary said that the testing capacity built would "help every single person in this country".
He said testing is "crucial to suppress the virus" and would "help us to unlock the lockdown".
Mr Hancock said the teams who increased capacity, had "joined in one of the greatest national mobilisations we've seen".
He added: "Setting stretching, ambitious goals in a crisis has a galvanising effect on everybody involved. It is a mission.
"If we hadn't been so bold, if we'd chosen a safer, easier path, I just can't see how we would have built the capacity that we need."
New Covid-19 NHS app will tell where the virus is spreading
A new Covid-19 NHS app will help to tell where the virus is spreading and help everyone to control new infections, the Government has said.
The new technology will inform people if they have been in close contact with someone who is transmitting the disease and take the action that they need to.
It forms part of the Government’s test, track and trace model, that it says will drive the infection rate down.
Mr Hancock said tracking and tracing will help to get the ‘R’ rate down and hold it down, which will then allow the lifting of lockdown measures.
Mr Hancock said the Government was prepared to increase the number of staff needed for the track-and-trace operation that was being rolled out.
"By mid-May, we will have an initial 18,000 contact tracers in place," he said.
"That work is under way as we speak and if it needs to be bigger, we will scale it as required.”
Lockdown was not imposed due to lack of tests
National testing co-ordinator Professor John Newton said the lockdown would have been imposed at the same time regardless of testing levels and said "levels of testing have not kept us in lockdown a day longer".
Speaking about hitting the "important milestone", he told the press conference: "Back in March the country moved into lockdown because the country was circulating widely, not because we didn't have enough tests.
"Cases were popping up with no obvious connection to other cases and the infection was entering the exponential growth phase and at that point access to limitless testing even if we had had it would've made no difference.
“The decision to enter into lockdown would have been the same and would've been taken at the same time.
"In the same way the route out of lockdown has not been blocked by low levels of testing.
“We can relax social distancing only when the Government's five tests are met, and that means particularly getting the infection rate right down.
"Testing will help to keep it out of control once we're out of lockdown but our levels of testing have not kept us in lockdown a day longer."
Pupils will only return to school when it is safe
Health Secretary Matt Hancock has vowed the Government would only allow pupils to return when it was safe to do so.
He said: "We are not going to re-open schools if it isn't safe.
"I'm confident, because we'll only do it when it is safe, it will at that point be entirely reasonable and normal again to send your children to school."
Prof Powis added: "The science is still evolving in terms of transmission between children, so we do need to be cautious as we think of re-opening schools and we will need to think carefully and advise the Government with appropriate information about how that can happen."
Science on immunity 'still emerging'
Prof Newton said the science on immunity "is still emerging" after being asked about a study showing some levels of immunity in people who had contracted coronavirus.
"A general rule would be that you would never make a decision based on a single study, so we would very much want to see that result replicated in other studies before we decided that was really the case," he said.
“It is obviously promising. I think people have said before in these briefings that it would be very surprising if there was no immunity after infection, but at the moment the science is still not precise about how much immunity you get and how long it lasts.”