How is DNA used in paternity testing?
There exists certain regions of human DNA which show variations between people. At each of these regions a person possesses two genetic types (known as alleles), one inherited from each parent. By looking at a number of these variable regions in a person a DNA profile is produced. And by comparing the DNA profiles of the mother and child it is possible to determine which half of the child’s DNA was inherited from its mother (maternal alleles). Thus, the other half must therefore have been inherited from the child’s biological father. . Another approach which could be taken but which has a few limitations is testing the DNA using mitochondrial genome. Proving a relationship based on comparison of the mitochondrial genome is much easier than that based on the nuclear genome. However, testing the mitochondrial genome can only prove if two individuals are related by common descent through maternal lines only from a common ancestor and is thus of limited value. How efficient is the testing?