D'Andrea, F., F. Fridez, and R. Coqouz. 1998. Preliminary experiements on the transfer of animal hair during simulated criminal behavior. Journal of Forensic Sciences. 43:1257-1258.

Just as with dog hair, cat hair is a common finding in the environment of cat owners. Often the hairs have been naturally shed and lack substantial hair roots. Although STR typing is always attempted if the root end of the hair is present, it may be unsuccessful, particularly if only a few hairs are presented as evidence. In that event, mitochondrial DNA (mtDNA) is extracted from the hair shaft. MtDNA is also more easily recovered from blood and tissue samples that have undergone environmental degradation. This is possible because mtDNA is present in hundreds of thousands of copies in each cell (as opposed to nuclear DNA in which there is only one copy per cell). MtDNA is inherited from the mother; animals related through the maternal line will have the same haplotype and can provide a reference sample if needed.

The region of mtDNA analyzed for forensic identification is called the control region, the hypervariable region, or the D-loop. The analysis consists of PCR amplification of the control region in either one large or two smaller sections followed by DNA sequencing of the entire region. The different sequence variants of the control region are termed "haplotypes". QuestGen Forensics has a database of 89 unrelated purebred cats with 5 unique haplotypes recognized thus far. An expansion of the region analyzed and the inclusion of a large number of mixed breed cats is expected to add many more haplotypes to the database. As in human mtDNA typing, in the event of a match the convention for reporting the significance is to simply state the number of times the haplotype it has been seen in the database.