©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 7 (4): 1226-1232 (2008) An improved extraction protocol for metagenomic DNA from a soil of the Brazilian Atlantic Rainforest J.H. Amorim, T.N.S. Macena, G.V. Lacerda-Junior, R.P. Rezende, J.C.T. Dias, M. Brendel and J.C.M. Cascardo Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, BA, Brasil Corresponding author: J.C.M. Cascardo E-mail: cascardo@uesc.br Genet. Mol. Res. 7 (4): 1226-1232 (2008) Received August 14, 2008 Accepted September 26, 2008 Published November 11, 2008 ABSTRACT. The need for the prospecting for and identiication of new biomolecules is a reality. Molecular techniques allow access to the metabolic potential of microorganisms via the isolation of DNA from environmental samples, i.e., without the application of micro- bial culture techniques. With its great biological diversity, the Atlantic Rainforest biome has a soil rich in organic matter, some components of which interfere negatively in the reactions necessary for the ex- ploitation of its biotechnological potential. Here, we describe a proto- col for the optimization of the treatment of soil samples before DNA extraction. The new methodology gives higher yield and quality of extracted DNA as compared with pre-existing techniques, facilitat- ing the ampliication and digestion of environmental DNA, and thus allows optimal exploitation of the genetic potential of the Atlantic Rainforest biome. Key words: Microbial DNA; Lysis; Polymerase chain reaction; Soil; Atlantic Rainforest