Postprint version. Published in Journal of Microbiological Methods, Volume 52, Issue 3, March 1, 2003, pages 389-393. Copyright © 2003 Elsevier, Inc. The definitive version can be found online at http://dx.doi.org/10.1016/S0167-7012(02)00210-5.
Extracting high-purity DNA directly from soil has become essential for the study of microorganisms in environmental samples. However, many soils contain compounds that inhibit enzymes involved in manipulating DNA. In this study, chemical flocculation using multivalent cations was investigated as a potential method for eliminating soil-based inhibitors during the extraction process. The addition of AlNH4(SO4)2 during extraction significantly reduced the co-purification of PCR inhibitors with minimal loss of DNA yield.