Mitochondrial DNA (mtDNA) is an important tool in forensic genetics, particularly when biological evidence is old, limited, or degraded. It is found in mitochondria, cellular structures involved in energy production. Unlike nuclear DNA, which is primarily located in the cell nucleus, mitochondrial DNA occurs in multiple copies within many cells. This abundance can make it useful when conventional nuclear DNA analysis is unsuccessful. Forensic scientists may examine mtDNA from challenging samples, including hair shafts without roots, old bones, and teeth. Such materials may contain highly fragmented nuclear DNA, while some mitochondrial DNA remains suitable for analysis. The usefulness of a sample depends on its condition, the amount of surviving genetic material, and the methods available in the laboratory. Mitochondrial DNA is generally inherited through the maternal line. Consequently, its sequence can be compared with that of maternal relatives to help investigate unidentified human remains or missing-person cases. This is particularly valuable when direct reference samples from the missing individual are unavailable but suitable samples from maternal relatives can be obtained. The analytical process involves extracting genetic material, examining suitable target regions, and determining the nucleotide sequence. Scientists then compare the resulting sequence with appropriate reference samples. Reliable interpretation requires validated procedures, contamination prevention, and careful documentation of the laboratory process. However, mtDNA has important limitations. Maternal relatives may share the same mitochondrial sequence, meaning that a match usually cannot uniquely identify one individual among all members of a maternal family line. Contamination, sequence variation within an individual, and limitations in the reference data may also complicate interpretation. For these reasons, mitochondrial DNA should generally be viewed as a complementary forensic method rather than a universal replacement for nuclear DNA profiling. When combined with other genetic findings, anthropological examinations, and investigative information, mtDNA can contribute significantly to human identification and the investigation of historical or unresolved cases. المصدر العلمي / Scientific reference: Mitochondrial DNA in Forensic Use — Epigenetics & Chromatin. PMC +1