What will a DNA test tell you?

Q: Does a DNA test tell you ethnicities (ex:puerto rican, swedish, French) or races (ex:black, white, Asian) I would like to finally know what makes me up, would I take a DNA test and get like spit from both my mother and father, how does it work?

A: No, it is not possible. Human DNA is complex, and there is no way that different ethnicities can be distinguished by some sort of test. Don’t confuse this with the DNA testing that can be done on dogs to tell which breeds make them up. Maybe one day we will be able to do this with human beings, but that day isn’t here yet. A DNA test can prove or disprove parentage and certain genetic markers for disorders can be found (for example, someone withcystic fibrosis in his or her family can be tested to see if he or she carries the gene), but we cannot break down human ethnicities at this time.