title: Residual soil DNA extraction increases the discriminatory power between samples.
abstract: Forensic soil analysis relies on capturing an accurate and reproducible representation of the diversity from limited quantities of soil; however, inefficient DNA extraction can markedly alter the taxonomic abundance. The performance of a standard commercial DNA extraction kit (MOBIO PowerSoil DNA Isolation kit) and three modified protocols of this kit: soil pellet re-extraction (RE); an additional 24-h lysis incubation step at room temperature (RT); and 24-h lysis incubation step at 55°C (55) were compared using high-throughput sequencing of the internal transcribed spacer I ribosomal DNA. DNA yield was not correlated with fungal diversity and the four DNA extraction methods displayed distinct fungal community profiles for individual samples, with some phyla detected exclusively using the modified methods. Application of a 24 h lysis step will provide a more complete inventory of fungal biodiversity, and re-extraction of the residual soil pellet offers a novel tool for increasing discriminatory power between forensic soil samples.
authors.affiliation: Australian Centre for Ancient DNA, School of Biological Sciences, University of Adelaide, Adelaide, Australia, jennifer.young@adelaide.edu.au.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Young
authors.forename: Laura S
authors.initials: LS
authors.lastname: Weyrich
authors.forename: Laurence J
authors.initials: LJ
authors.lastname: Clarke
authors.forename: Alan
authors.initials: A
authors.lastname: Cooper
mesh_terms: D004269:DNA, Bacterial / Q000302:isolation & purification*; D004271:DNA, Fungal / Q000302:isolation & purification*; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D044707:Forensic Sciences / Q000379:methods; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D006863:Hydrogen-Ion Concentration; D056186:Metagenomics; D016133:Polymerase Chain Reaction; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D004269:DNA, Bacterial; D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D012987:Soil