Developing a High Throughput Protocol for Using Soil Molecular Biology as Trace Evidence

Using soil molecular biology to make a traceable fingerprint has been proposed as putative method for forensic science. One unknown of this method is how the soil microbial community responds to contrasting conditions for storage and handling. To examine this we compared field fresh sample to soil samples stored one of six ways (4 ̊C, -20 ̊C, -80 ̊C, air dried, freeze dried, and oven dried) for 5 weeks. Fingerprint profiles were made with PCR of the V3 region of the 16S rDNA and processed using capillary electrophoresis-single stranded conformation polymorphism (CE-SSCP) on a 3130 genetic analyzer. An Analysis of Similarity showed that there was no significant change to soil bacterial DNA profiles during storage. When different soil collection sites were compared significant differences were observed, illustrating that different soil microbial communities react differently to storage, even over a relatively small geographic space.