DNA from wood - A simple approach facing a challenging matrix - A preliminary study.

Plant DNA barcoding has proven to be a handy tool for identifying botanical species. However, extracting DNA from woody materials is often a challenging task. Forensic applications, therefore, must be able to overcome the technical difficulties of this nature. A simple and successful adaptation, through a widely used method in forensic laboratories, using chemistry based on magnetic DNA isolation technology and a robotic platform, is presented here. The model case was the application of this adapted DNA extraction method for the identification of Aspidosperma spp., a genus comprising several species in all biomes of Brazil, including Cerrado and Rain Forest. Such technology adaptation can aid in the identification of seized material and help in investigations involving illegal logging and deforestation, ultimately contributing to environmental protection.

Forensic botany and forensic chemistry working together: application of plant DNA barcoding as a complement to forensic chemistry-a case study in Brazil.

Recently, Brazilian Federal Police used forensic chemistry and forensic botany techniques on a case. Two packets containing fragmented plant matter were seized and sent for forensic analysis. Forensic chemistry, the gold standard for evaluating plant material suspected to contain illicit substances, did not find illicit materials. Gas chromatography coupled mass spectrometry (GC-MS) identified thujone in the botanical material. Thujone is a chemical compound naturally found in many plant species, notably Artemisia absinthium. Because doubt remained, we next used plant DNA barcoding methods. Total DNA from plant tissue fragments was extracted and five different DNA regions were amplified, sequenced, and analyzed using plant DNA barcoding methods. Genetic analysis yielded 30 good quality sequences representing five taxa. Most specimens were identified as A. absinthium. Few studies focus on practical forensic applications of plant DNA barcoding methods using a case solved in a forensic laboratory with its difficulties and limitations. To the best of our knowledge, this is the first study to report an effective joint effort of forensic chemistry and botany techniques to assess plant material in Brazil. The availability of a new technical approach for the genetic sequencing of plant species will enhance many forensic investigations and inspire similar initiatives.