DNA Mitochondrial

For highly tainted samples, it is from time to time not possible to get a whole profile of the 13 CODIS STRs. In these situations, mitochondrial DNA (mt DNA) is sometimes typed due to there life form a lot of copies of mtDNA in a cell while there may only be 1 to 2 copies of the nuclear DNA. Forensic scientists amplify the HV1 and HV2 regions of the mtDNA, and then sequence each region and compare single nucleotide differences to a orientation. Because mtDNA is maternally inherited, directly linked maternal relatives can be used as match references, such as one's maternal grandmother's daughter's son. A difference of two or more nucleotides is generally considered to be exclusion. Heteroplasmy and poly-C differences may throw off straight sequence comparisons, so some expertise on the part of the analyst is required. mtDNA is useful in determining clear identities, such as those of deficient people when a tenderly linked relative be able to be found.