Private DNA labs allow today to check your DNA and also check whether your father or your mother is really your biological father/mother. A daughter or a son shares roughly 50% of its DNA with the father and 50% of DNA with the mother.
Consequently, if you test your DNA and your father DNA or mother DNA, it is possible to know how much DNA is shared between the parents and the infant.
FamilytreeDNA test lab
Once again two test kits should be ordered. The procedure at familytreedna.com & the DNA screening software is different from 23andme but the results should be the same. In the case of familytreedna.com, you receive a kind of toothbrush which you will use to scrap inside your cheek. Then you will put this little toothbrush into a test tube and send it back to the test lab. familytreedna.com has a web application which compares DNA results from different users to find if there are related. Find below a screenshot of the Family finder section.