FIG. 3.

Hybridization of whole-cell (A) and RNA-extracted (B) sediments with ³²P-labeled universal eubacterial 16S rRNA-targeted oligonucleotide probe UNIV 342. Fifty microliters of the whole-cell extract (ca. 10⁵ to 10⁶ cells) and 3 ng of extracted RNA was immobilized on the membrane for each depth sample (slot). Sediment depth and average relative hybridization density (optical density) for each depth is shown. Average hybridization signal is the result of replicate blots from replicate core samples indicated as REP 1 and REP 2.