The presence of someone's DNA in your mouth after kissing can vary depending on various factors such as the intensity and duration of the kiss, the amount of saliva exchanged, and individual differences in DNA shedding rates.
When you kiss someone, a small amount of their DNA may be transferred to your mouth through saliva and skin cells. However, it's important to note that this DNA transfer is usually minimal and not enough to have any significant impact on genetic testing or identification.
In most cases, any foreign DNA introduced through kissing is likely to be washed away or degraded relatively quickly by the enzymes and acids present in saliva. Studies have shown that foreign DNA in the mouth typically doesn't persist for more than a few minutes to a few hours after the kiss.
It's essential to remember that DNA testing and identification require specific procedures and controlled sample collection, such as buccal swabs, blood samples, or other approved methods, to obtain reliable and accurate results. Kissing someone casually will not have any long-term impact on your DNA or affect any genetic testing results.