ABSTRACT
Vegetative materials such as stems, roots, and seeds found in a crime victim’s stomach contents, on a suspect’s clothing, or at the crime scene can be valuable evidence for providing investigative leads in criminal and civil litigations. Currently, the identification of vegetative materials still relies on microscopic and morphological methods. Most seeds from a particular species generally have the same microscopic appearance, especially those recovered from stomach content or in excretions. Therefore, the use of a DNA typing technique could provide a more reliable way for seed identification.
To further explore the use of tomato evidence in forensic investigations, we have developed a procedure to extract high quality DNA from tomato seeds for subsequent DNA- AFLP (Amplified Fragment Length Polymorphism) analysis. It was found that DNA in tomato seeds is often protected from acid degradation during stomach digestion by their tough exterior seed coat. The DNA-AFLP method was performed and we have found that DNA obtained from single seeds could be used for polymerase chain reaction analysis. From the AFLP results, several DNA markers for identifying seeds from tomato and other plant species were identified. These data on DNA analysis of tomato seeds indicate that AFLP analysis is a viable procedure for the individualization of seeds from stomach contents in medico-legal and forensic investigations.
