Research Article of American Journal of Agricultural Research
Study of soil DNA extraction and soil microbial communities
Hamid kheyrodin1 and Sadaf Kheyrodin2
1Assistant professor in semnan university –Iran
2Student MS.c in Urban planning in Mashad azad university- Iran
Molecular analyses for the study of soil microbial communities often depend on the extraction of DNA directly from soils. These extractions are by no means trivial, being complicated by humic substances that are inhibitory to PCR and restriction enzymes or being too highly colored for blot hybridization protocols. Many different published protocols exist, but none have been found to be suitable enough to be generally accepted as a standard. Most direct extraction protocols start with relatively harsh cell breakage steps such as bead-beating and freeze-thaw cycles, followed by the addition of detergents and high salt buffers and/ or enzymic digestion with lysozyme and proteases. After typical organic extraction and alcohol precipitation, further purification is usually needed to remove inhibitory substances from the extract. This review presents an overview of the available methods to achieve this challenging objective. DNA was extracted from 100g of soil using direct lysis with glass beads and SDSfollowed by potassium acetate precipitation, polyethylene glycol precipitation, phenol extraction and isopropanol precipitation.
Keywords: PCR, soil microbial, DNA