Which type of sample can mitochondrial DNA analysis be performed on?

Mitochondrial DNA analysis can be performed on hair samples without roots because mitochondrial DNA (mtDNA) is present in the mitochondria, which are found in the hair shaft itself. This means that even if the hair does not have the follicular root attached, it can still yield valuable genetic information.

Unlike nuclear DNA, which is typically extracted from the roots of hair, mtDNA can be found in the hair shaft, allowing for analysis in cases where the root is absent. This is particularly useful in forensic science when dealing with hair found at a crime scene, as it can provide a means of identification through maternal lineage.

In contrast, other sample types like blood or skin typically provide nuclear DNA, which, while very informative, does not benefit from the same techniques as mtDNA in situations where those sample types may not be available or are compromised. Thus, the ability to analyze mtDNA from hair samples without roots is a unique and valuable aspect of mitochondrial analysis in forensic investigations.