FIG. 1.

Comparison of DNA fragment size distributions and relative DNA yields obtained with the nine DNA extraction procedures described in Table 2. Five-microliter portions from three replicate extractions were pooled, digested with RNase, and electrophoresed on a 0.8% (wt/vol) agarose gel. The results obtained for wetland sediment are shown. DNA extracts obtained from forest and agricultural soils produced similar results. Lane M contained 500 ng of λ-HindIII marker.