Check out some of the chain of custody features Crystal Health Group implement and the different sample types that can be collected to be used for DNA, Drug and Alcohol testing.
Crystal Health Group: https://www.crystal-health.co.uk/
DNA Testing Services: http://www.dnatestingclinics.co.uk/
Drug Testing Services: https://www.drugtestingclinics.co.uk/
London Drug Testing Services: https://www.drugtesting.london/