An expansion of coronavirus testing for hospital patients and health and social care staff has been announced by the Scottish government.
Health Secretary Jeane Freeman said frontline health professionals would receive twice-weekly tests.
Emergency hospital admissions will also be tested from next week, and will be extended to all admissions next month.
Testing will also be expanded in the coming months for care home visitors and staff.
However, the GMB union said it would not be until March that all at-home care workers received regular tests, which it described as "shameful".
And opposition politicians accused the Scottish government of making similar promises in the past without delivering, and said the measures should have been introduced months ago.
Ms Freeman said the roll-out to health professionals would include frontline staff in hospitals, the Scottish Ambulance Service, Covid assessment centres in the community and healthcare professionals who visit care homes.
It will be phased in from next week, with the aim of being completed by the end of December.
Visitor testing will be initially introduced in up to 12 care homes across four local authority areas from 7 December, with full roll-out planned for January.
To facilitate Christmas visiting in all care homes, PCR testing will be provided for those that do not have access to lateral flow testing by that time.
Ms Freeman said guidance on visiting arrangements over Christmas is to be published shortly.
Testing for home carers will start to roll-out from mid-January.
December will also see the start of a testing programme for students before they return home for Christmas.
And targeted geographic testing will be trialled in communities covered by NHS Ayrshire and Arran, Forth Valley, and Greater Glasgow and Clyde, which are currently under level four restrictions.
This trial will utilise a mixture of existing and new testing technology, and will include an asymptomatic test site with capacity to test up to 12,000 people over the course of a week in Johnstone, Renfrewshire.
The results of these pilots will inform plans for a wider programme of targeted community testing in early 2021.
Ms Freeman said the plans would "provide further protection for our communities, our extraordinary health and social care staff and the people they serve".
She added: "This expansion is possible because of increases in our testing capacity, delivered through our new regional hub laboratories and supply of new testing technologies, which will help us suppress Covid to the lowest levels possible as we face a challenging winter ahead."
'Lack of detail'
Scottish Labour MSP Monica Lennon said the Scottish government had made similar promises about testing "time and time again", and said there was a "worrying lack of detail" on how it would work.
She added: "SNP ministers were warned months ago to test all hospital workers routinely to help slow virus transmission, but today the SNP government announced that it will be December before this happens.
"For at-home care workers, they will have to wait until March - a full year on from the start of the pandemic."
And Rhea Wolfson of GMB Scotland added: "In all probability it will be March 2021 before every home care worker has testing at work and staff could very well be receiving their vaccinations before they ever receive a test.
"Last March the first minister told us that Scotland was prepared for this pandemic and that Scotland had among the best testing capacity in the world. This was a tissue of lies.
"Covid has exposed how poorly Scotland's carers are valued and today's statement is the equivalent of kicking an exhausted workforce when they are already down."