Effects of storage conditions on soil molecular biology for forensic science purposes

Abstract

The object of this project is to identify changes in soil microbial community DNA and Fatty Acid profiles caused by storage, using capillary electrophoresis single‐strand conformation polymorphism (CE‐SSCP) and fatty acid methyl ester (FAME) analysis.There were six different storage treatments tested (−80°C, −20°C, 4°C, freeze dried, air dried, oven dried) on soil samples collected from 4 different locations in Nebraska. Samples were taken at a depth of 0.0 cm to 5.0 cm from three biological replicates at each collection site. After collection, soils were sieved and subsamples were placed into each storage treatment for five weeks then analyzed, with the exception of one subsample (fresh) which had DNA and fatty acids extracted within 36 hours of collection. Additional fresh samples were collected and processed two weeks after initial collection and seasonally.The CE‐SSCP and FAME analysis will illustrate the microbial community and its diversity for an individual soil sample through the number of peaks, molecular size of peaks and relative peak heights. Using statistical analysis it can be determined which storage treatments altered the soil microbial community profile when compared to the fresh subsample. Results will be presented to show the effectiveness of these two methods to detect small variations in the soil microbial community. Funded by National Institute of Justice (25‐6228‐0159‐001).