The Scottish government's new "test and protect" strategy will go live on Thursday, the first minister has confirmed.
Ms Sturgeon said the scheme will mean anyone with symptoms of Covid-19 should take "immediate steps" to be tested.
They and their household should then self-isolate until the results of the test are known.
If the test is positive, people will need to provide the details of everyone they have had close contact with.
These people will then be contacted by specialist tracers, and will need to "immediately" self-isolate at home for 14 days.
This means they should go home from work straight away, and "take care to come into contact with as few people as possible" - although it is only if they are displaying symptoms or test positive that other people in their households will need to self-isolate.
Ms Sturgeon defined a "close contact" as being:
- People within your household
- People with whom you have had face-to-face contact
- People you have been within two metres of for a period of 15 minutes or more
Those contacted will not be told the name of the person who tested positive in order to protect their privacy.
The first minister stressed that self-isolation means only leaving the house if it is to go for a coronavirus test - and not for exercise or to get food or medicine.
She said the new scheme would see testing on a scale that has never been done before in Scotland.
It will be introduced across all of the country's health board areas on the same day as the lockdown restrictions are due to be eased.
How will test and protect work?
Ms Sturgeon said Scotland now had the capacity to do 15,000 tests for Covid-19 every day through a combination of NHS labs, universities, the Scottish Blood Transfusion Service and the UK government's Lighthouse lab in Glasgow.
She said about 700 contact tracers would be needed in the first phase of project - although a pool of 2,000 will be in place by the end of the month.
Special contact tracing software has been piloted and will also be introduced on Thursday, with Ms Sturgeon saying information will be handled by the NHS and will not be accessible by the Scottish government.
Guidance will also be given to employers "making clear they should support any member of staff who is asked to self-isolate through Test and Protect", Ms Sturgeon said.
People may be able to work from home if they feel well enough, but bosses should not ask people to go into work under these circumstances, she added.
Ms Sturgeon also said the Scottish government has been in touch with the UK government to "ensure that employment rights and entitlement to benefits, including statutory sick pay, take account of the fact that people might be off work or unable to attend appointments through no fault of their own".
There is no doubt that "test and protect" is asking a lot of people.
It needs speed. Can the testers turn around results quickly and accurately - perhaps in under 24 hours - so that people know if they are positive?
The role of contact tracers will be crucial. Will they be able to reassure people and ask the right questions, so they can make the right decision about who will be defined as a contact?
While shoppers passing in a supermarket aisle might not count, this could affect large numbers of staff who work together. Could a whole fire crew be taken off the front line because a colleague tests positive and they can't socially distance at work?
"Contacts" would be asked to self-isolate even if they have no positive symptoms or a positive test result. It is asking a lot of employers and their staff and could directly affect people's livelihoods.
Test and protect will need public support - and the public to take action.
The first minister said the new scheme would be crucial in limiting the spread of coronavirus as the country begins to open up again.
And she said it should not be looked on as being optional - with everyone needing to play their part to ensure it is successful by agreeing to fully self-isolate when asked to do so.
Ms Sturgeon said: "Test and Protect is a really important tool for us in the period ahead. The more effective it is, the more of the lockdown restrictions we will be able to lift.
"It is going to require exactly the same spirit of solidarity and care for each other as lockdown has done. It will be a collective national endeavour."
A public awareness campaign will start later this week, with further information being delivered to every household in the country next month.
The Scottish Conservatives said Ms Sturgeon's pledge on increased testing would be meaningless unless the additional capacity was actually used.
The party said the Scottish government had rarely carried out even half of the 10,000 test a day target it had previously set, with leader Jackson Carlaw saying it meant that "thousands of care home residents, workers and their families" were going untested.
Mr Carlaw added: "Exiting lockdown will be dependent on this test, trace and isolate system, and we very much want that to succeed. But until the issue of testing is sorted, there is little hope that it will."
Meanwhile, Ms Sturgeon also revealed that a total of 2,291 patients have died after testing positive for coronavirus, an increase of 18 from Monday.
There are 1,200 people in hospital with confirmed or suspected Covid-19, a decrease of 69 from the previous day, and the number of people in intensive care has fallen by four to 36.