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Table 1 Confirmation of the presence of bacterial life in terrestrial soil samples.

From: Measurement of microbial activity in soil by colorimetric observation of in situ dye reduction: an approach to detection of extraterrestrial life

Soil Type Plate Count1 (viable cells/g soil) Fluorescence2 (ng DNA/g soil)
Red sand 2.74 × 104 3.68
Silica sand ND ND
Beacon Valley, Antarctica ND ND
Lake Boney Basin, Antarctica 4.2 × 103 38.9
Blank (reagents only) 0 0
  1. Data are means of three replicates. Standard deviations were less than 5% for all results. 1Soil was suspended in distilled H2O, diluted, and an aliquot spread onto Plate Count Agar plates for quantification of colonies. Counts were taken after 48 h. 2Our detection limit was about 1 ng DNA/g soil. A 0.5 g amount of soil was used for each extraction. ND = not detected