ABSTRACT
The ultimate downstream application should dictate the methods used for soil sampling, DNA extraction and purification, and library construction and screening. The major factors to be considered while isolating soil metagenomic DNA for various applications are discussed in this chapter. Large-insert libraries are more appropriate to recover complex pathways that are encoded by large gene clusters or large DNA fragments for the characterization of genomes of uncultured soil microorganisms. To achieve substantial representation of the genomes from rare members of the soil community, it has been calculated that libraries containing 10,000 Gb of soil DNA is needed in library construction. A variety of approaches may be employed for analyzing the soil metagenome, depending on the specific aims of the study. The ultimate downstream application should dictate the methods used for soil sampling, DNA extraction and purification, and library construction and screening.
