DNA From Processed and Unprocessed Wood: Factors Influencing the Isolation Success

• NCJ Number: 227240
• Journal: Forensic Science International: Genetics Volume: 3 Issue: 3 Dated: June 2009 Pages: 185-192
• Author(s): Yanti Rachmayanti; Ludger Leinemann; Oliver Gailing; Reiner Finkeldey
• Date Published: June 2009
• Length: 8 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

Since the identification of the origin of wood is particularly important for identifying illegally harvested and traded timber and wood products, this study describes success rates of DNA isolation from wood based on a simple, previously published extraction protocol.

Abstract

Study data confirm previous reports that wood tissue is a suitable material for extracting extra-nuclear genetic material usually described as "cpDNA," even though wood does not contain chloroplasts. Plastids, such as amyloplasts, containing DNA usually extracted from chloroplasts occur in parenchyma cells of wood tissue. The occurrence of cpDNA in numerous copies enhances the likelihood for successful amplification of extra-nuclear genetic information. The main factors that influenced the success of PCR amplification were the size of the amplified fragment and the processing status of the wood. Short fragments and unprocessed wood resulted in higher success rates. The success rate was also dependent on the age (storage duration) of the wood probe as well as on the investigated species. Amplification success was higher if DNA was isolated from outer sapwood (without cambium) compared to DNA isolated from the transition zone between sapwood and heartwood and the inner heartwood; however, inhibitor tests also indicated more PCR inhibitory substance in the outer sapwood compared to transition wood and heartwood. The addition of polyvinylpyrolidone to the lysis buffer improved the amplification success when inhibitory substances were present. A total of 406 wood samples were analyzed. Out of the 332 samples that belonged to the family Dipterocarpaceae, 181 were collected from natural forests or plantations in Southeast Asia; 151 were from wood enterprises or wood-processing facilities in Germany. Detailed descriptions are provided on materials and methods used. 3 tables, 5 figures, and 29 references