Research on mitochondrial DNA (mtDNA)

BioTe21 Genetic Identification Lab also undertakes a sequence analysis of mitochondrial DNA (mtDNA) in a region of highly variable sequences HVS-I and HVS-II.

In genetic identification the mitochondrial DNA is taken into consideration only in cases when genomic DNA (gDNA) material is not sufficient, especially when it has obviously been damaged. The number of copies of particular STR systems in a single cell equals 2 and is equivalent to a pair of chromosomes, one from a mother and one from a father. In contrast, the number of circular molecules of mitochondrial DNA in a single cell may reach a few thousand. Therefore, the mitochondrial DNA is used when genomic DNA has been damaged. The probability that mtDNA copies have been intact in a damaged genetic material is considerably greater, so that they enable identification when standard genomic DNA analyses fail. The only problem is that mitochondrial DNA analysis isn’t as accurate and reliable as genomic DNA analysis even though similar testing methods are applied (the number of genetic differences in mtDNA is smaller than in genomic DNA).