ABSTRACT
We are developing methods in our laboratory to produce molecular fingerprints from soil microorganisms as a means to differentiate soils and possibly identify sources of soil-derived fugitive dust. The methods described here are based on the extraction of microbial DNA from soil and dust samples which contain billions of microorganisms per gram. DNA fingerprinting involves the following: (l) soil sampling, (2) treating the soil to break open microbial cells, (3) extracting and purifying the DNA that is released from cells, (4) using polymerase chain reaction (PCR) to copy specific gene fragments from the DNA, and (5) generating a fingerprint from the gene fragments by electrophoretic separation in an analytical gel. The number and diversity of gene fragments in a fingerprint will depend on the specificity of DNA “primers” used in PCR to copy DNA. In this chapter we present our preliminary 194 results on the extraction and analysis of microbial DNA from agricultural soils and bulk dusts from California’s Central Valley. We describe experimental methods, technical difficulties observed, and basic assumptions that need to be considered in evaluating whether DNA fingerprinting can be applied to the problem of identifying sources of soil-derived fugitive dust.
