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 early opportunity to retrieve DNA evidence will assist in the detection of this crime Donald McLeod crime prevention officer

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.