Powers allowing police forces to keep the DNA of people accused of sexual or violent offences have come into force.
The move allows greater powers over the storage of DNA
The measure will allow the police to store such information on a database, even if there is no conviction.
Currently, DNA must be destroyed if it belongs to an accused of sexual or violent crimes if there is no conviction obtained.
The changes are contained in the Police, Public Order and Criminal Justice (Scotland) Act 2006.
They will allow police to retain DNA samples for up to three years and apply for an extension if deemed necessary.
Justice Minister Cathy Jamieson said: "It represents a sensible balance between those who believe that the police should retain all the DNA that they take and those who argue that police powers to keep DNA should be limited.
"The focus on violent and sexual offences is proportionate, given the seriousness of those offences."
The act, which came into force on New Year's Day, was given royal assent last year year and has already provided the police with powers to crack down on knife crime, sex offenders and football-related disorder.
Mandatory drug testing on arrest for anyone aged 16 or over who is suspected of a drugs or drug-related offence, or other offences including theft, will be brought in during 2007 as part of the act.
Those who test positive for heroin, cocaine or both will be required to have a drugs assessment which will initially be implemented on a pilot basis.