A mitochondrial DNA test is a test to do when one wishes to establish a common maternal line between two or more people. For example, people may wonder whether they have a mother in common. MtDNA testing (as it is sometimes known) or mitochondrial DNA testing is very accurate at determining maternal lineage. MtDNA is less complex than the other type of DNA in the cell, known as nuclear DNA and has very specific uses, unlike nuclear DNA which is used for a wide range of relationship tests. Mitochondrial DNA can easily be gathered by means of a simple mouth swab although the results to the MtDNA test tend to take a while longer than results to, for example, a DNA paternity test.
Mitochondrial DNA testing is reliable because this type of DNA has a relatively low rate of mutation. Mitochondrial DNA is not found in the cell nucleus like nuclear DNA, it is in fact found in the cell mitochondria.