Regardless of the duration of a kiss, DNA remains in the mouth for at least one hour after kissing another individual, states Medical Daily. When kissing, two people swap bacteria, bodily fluids and parts of their genetic code.
The DNA of another individual that remains in a person's mouth can be found through amplification an hour after kissing, according to Medical Daily. This is the process of artificially increasing a particular DNA fragment found in a person, explains the free dictionary. Within just 10 minutes of kissing, the full genotype of another person's DNA can be found versus simply finding the presence of DNA an hour later states Medical Daily.