FIG. 7.

All first injection cycles of VL2. A fresh sample was used for all sequences except cycle 5, which used the same sample as for cycle 4 but was stored for approximately 84 sols before nutrient injection. All soil samples were taken from the same site except the sample for cycle 3, which was taken from under Notch Rock. All data have been corrected for background counts observed prior to nutrient injection. [Reprinted from Levin, G.V. and Straat, P.A. (1979a) Completion of the Viking Labeled Release Experiment on Mars. J Mol Evol 14:167–183, 1979; Journal Molecular Evolution © by Springer-Verlag, 1979; with permission of Springer.]