The DNA behind a big smooch.
A long passionate kiss or a quick kiss on the lips does more than show feelings. Besides exchanging bacteria and mucus; you also leave your genetic code. The DNA left behind in a kiss will hang around for one hour. Good news for law enforcement. A person’s saliva could hold evidence in cases of assault or even infidelity.
Research done (in Slovakia) relied on detecting the Y chromosome; meaning only a man’s DNA in women’s saliva was detectable. They found that full DNA profiles were retrievable after one hour. Further research is being conducted to see if profiles can be obtained after longer periods and from corpses (New Scientist, 2013).
If the above wasn’t convincing enough; a London court sentenced an armed robber to 13 yrs. in prison, based on the genetic fingerprint that his saliva left behind on the bank’s security screen. You can read the story from the link below (Chicago Tribune).
DNA testing has advanced to the point that STRs profiles, useful for identification purposes, can now be retrieved from biological samples recovered after an explosion from highly burned and degraded bomb debris (Berti, et. al, 2011).
For those interested in forensic science, the library currently has holdings for 13 titles of online journals on forensics. Check out the link here.
New Scientists. 26 Jan 2013. http://www.newscientist.com/article/mg21729014.900-lingering-kiss-dna-persists-in-the-mouth-after-smooch.html
(Forensic Science International: Genetics, DOI: 10.1016/j.fsigen.2012.07.007).
DNA saliva test links man to bank robbery: [FINAL, M Edition]Chicago Tribune (pre-1997 Fulltext) [Chicago, Ill] 25 Mar 1992: 6.
Berti, F. Barni, A. Virgili, C. Colozza, F. Maiorino, M. Tocca, The recovery of DNA profiles from saliva and touch evidences after postal bomb explosion, Forensic Science International: Genetics Supplement Series, Volume 3, Issue 1, December 2011, Pages e471-e472, (http://www.sciencedirect.com/science/article/pii/S1875176811002368)
Image credit: http://en.wikipedia.org/wiki/File:Kuss.jpg