Short Answer 
Kissing can result in the temporary transfer of DNA through saliva, which can remain in a person’s mouth for up to an hour before being washed away by natural processes. However, this DNA is not permanent and does not integrate into the recipient’s genetic material, meaning it only exists temporarily.
Step 1: Understanding DNA Transfer
When two individuals kiss, they can transfer their DNA through saliva. This transfer occurs because saliva contains cells that carry genetic information. During a kiss, these cells can mix, leading to a temporary exchange of DNA between the partners.
Step 2: Duration of DNA Presence
The DNA from a kiss can remain detectable in a person’s mouth for up to an hour. However, this presence diminishes over time due to the body’s natural cleansing processes. The factors influencing how long DNA remains detectable include:
- Saliva production and its ability to wash away DNA.
- Swallowing, which can remove the DNA from the mouth.
- Avoiding eating or drinking immediately after the kiss.
Step 3: Temporary Nature of DNA
It’s crucial to understand that the DNA transfer from kissing is not permanent. It does not integrate into the receiver’s genetic material, existing only temporarily in the mouth. Forensic scientists may detect this DNA under specific circumstances, but it is not a lasting change in the individual’s DNA profile.