As submitted by the proposer: NIJ funding is sought to evaluate an easily deployable, efficient and inexpensive method for collecting postmortem DNA samples. Depending on the scale of the event and the condition of the remains, laboratories may not be able to efficiently deal with the sheer number of samples or lack experience with certain types of "challenging" samples, such as bone. Current guidelines for sampling may be further complicated due to a lack of basic resources at the site of the disaster. By evaluating the overall success of collecting and processing postmortem samples collected on Indicating FTA® cards, this study will benefit persons in the field collecting samples and the labs tasked with processing the samples. The properties of FTA® cards make them suitable to collect samples from both recently deceased individuals and decomposed bodies and presents a good alternative to other extractions methods from tissue or bones. Moreover, FTA® cards are widely used in forensic labs and present an ideal media for easy shipping due to their small area and stability at room temperature.
A pilot study has already established the feasibility of these types of analyses from severely decomposed bodies. The proposed research is designed to expand on this through a controlled study examining the efficacy of postmortem DNA sample collection and profiling using FTA® cards. Three replicate trials, each using four human cadavers, will take place during different seasons to evaluate weather and temperature effects on DNA yield and rates of degradation. Through an incision into muscle tissue, a foam collection swab will be inserted and then the swab will be rubbed on an Indicating FTA® card until the color change indicating transfer is observed. Two collections will be taken from each individual 10 times during the course of each trial (day 0, 5, 10, 15, 20, 25, 30, 35, 40, 45) or as soft tissue preservation allows. Both quantity and quality of DNA yield will be evaluated to determine the suitability of processing this type of postmortem sample in a forensic DNA laboratory. These results will be correlated to postmortem interval and accumulated degree-days to evaluate the methods efficacy over time and success rate based on different environmental conditions.
Guidelines will be developed for a simplified and cost-effective approach to efficiently collect large numbers of postmortem DNA samples that do not require specific preservation or storage conditions, are easy to ship and that most forensic laboratories are already equipped process.