Mitochondrial DNA (mtDNA) is present in the mitochondria of every cell in the human body. The mitochondria are the energy-producing bodies of a cell and are present in large quantities in human cells. Therefore, if a sample is highly degraded, it is possible that mtDNA can still be successfully analyzed even if standard DNA techniques have failed.
Mitochondrial DNA analysis is recommended with the following types of forensic samples:
- Cases with degraded or small samples that have not yielded results using conventional STR analysis (e.g. aged bone or teeth, aged or degraded tissue, and minute quantities of blood or other body fluids)
- Samples such as cut or shed hair which do not contain a root and thus will not work using conventional STR analysis
- Samples that have been subjected to the environmental extremes of heat, humidity, or burning
MtDNA is maternally inherited and is passed on to both daughters and sons. Therefore every child (male or female) of a particular woman has an exact copy of his or her mother’s mitochondrial DNA. Since mutations occur only once every 50 generations, a maternal line can be traced back many generations using mitochondrial DNA analysis. This means that every individual within the same maternal lineage will possess the same mtDNA. This makes mtDNA analysis useful in a few ways:
- When analyzing evidence from a case in which a known reference specimen from a victim or immediate family member is not available for comparison
- When a male suspect cannot be located or is not willing to provide a sample
In both instances above, a maternally-related individual could be used in place of a direct reference standard.
Mitochondrial DNA sequence analysis, while not suitable for every case, is a proven technology useful when standard STR-based approaches have been attempted and found to be uninformative. Orchid Cellmark is committed to providing high quality, and timely mtDNA data. A complete written report will be issued for every case.
For a brochure on Orchid Cellmark’s mtDNA Analysis services, please
click here.
To submit a case, click
here. Questions? Please call
1-866-TEST-DNA (837-8362).