Ancient DNA researchers now routinely target the petrous bone when it is available, drilling into it to extract a small amount of powder that can then be processed in specialized laboratory environments.

Teeth are also excellent sources.

The dense outer casing of enamel protects the biological material inside, and dental pulp — the soft tissue at the center of the tooth — can preserve DNA in good condition for thousands of years.

The 2025 Colombia study used both of these approaches.

The research team extracted DNA from the petrous portion of temporal bones and from teeth, applying the standard protocols developed over the past decade of ancient DNA research.

Once extracted, the DNA must be processed in strictly controlled laboratory environments to prevent contamination — the introduction of modern DNA from the researchers themselves or from ambient sources.