The Influence of Tanning Chemical Agents on DNA Degradation: A Robust Procedure for the Analysis of Tanned Animal Hide—A Pilot Study

Abstract

Illegal wildlife trade is currently on the rise, and it is becoming one of the most lucrative crime sectors. The rarer the species, the higher the demand. Wildlife trade falls under international regulations, such as the CITES convention. Proving that this convention has been violated is a complex process and can be very difficult to do. DNA analysis methods remain (in many cases) the only way to determine whether a certain specimen originated from a protected animal species, a specific individual, or a species in which it is legal to trade. Tanned animal hides are a specific type of specimen. With this type of biological material, obtaining amplifiable DNA is often difficult. This pilot study aimed to map the effect of the chemicals used in the tanning process on the degradation of the DNA yielded from such samples. The DNA was quantified using two different approaches: qPCR and Qubit fluorometry. The degree of DNA fragmentation was assessed by determining the degradation index. The results indicate that reagents containing chromium have the greatest influence on DNA degradation. However, by using the presented protocol, enough amplifiable DNA can be obtained from hides treated with aluminum-based reagents.