Bus drivers in the west of Scotland are to be issued with "spit kits" in an effort to cut the number of assaults.
Driver Hamilton Edgar tests the kit
The DNA swab packs will allow First Bus drivers who have been spat on to collect a sample to pass to Strathclyde Police for analysis.
Last year about a third of attacks on First drivers involved spitting and it is hoped the initiative will increase the number of arrests.
The police said they will monitor the scheme's success with a view to introducing it in other workplaces.
The kits contain a pair of sterile latex gloves, a collection bag and two sterile swabs to be used to remove the sample from the skin.
Alan Pert, First Bus security manager in Glasgow, said: "We are hopeful that these kits will act as a powerful deterrent to people spitting on drivers.
"We would urge people to think about how easily we can trace them through their DNA.
"It is even more accurate than a thumbprint and is similar to leaving a signature at the scene of a crime".
Chief Inspector Donald McLeod, the force's crime prevention officer, said: "Assaults of any kind on persons going about their business should not be tolerated.
"The early opportunity to retrieve DNA evidence will assist in the detection of this crime.
"Over the coming months we will monitor progress and thereafter, where appropriate, consider further opportunities to implement this strategy in other workplaces such as hospitals "