FIG. 2.

Amplification kinetics of 30 different 16S rDNA sequences: detection signal value versus PCR cycle number. The templates used were different 16S rDNA amplicon samples, and three different amounts (1 ng, 200 pg, and 40 pg) were tested. (A) The target was a 16S rDNA amplicon from E. coli. (B) The target was a 16S rDNA amplicon of clone DA001. (C) Normalized results of all experiments and parallel experiments performed with 10 pure-culture organisms (30 kinetics experiments). (D) Normalized results of all experiments and parallel experiments performed with 20 environmental sequences (60 kinetics experiments). The slopes were used to calculate the amplification factor per cycle (1.341 in panel C and 1.346 in panel D). The error bars indicate the minimal and maximal deviations in the data sets.