Experimentally measured time course of RNA and PPi simultaneously measured from the same sample at (A and D) T7 RNAP concentrations varying from 0.05 to 0.8 μM, (B and E) each of the NTP concentrations varying from 0.4 to 4.0 mM, and (C and F) Mg(OAc)2 concentrations varying from 2 to 20 mM. The time points were 0, 5, 15, 30, 45, 60, 75, 90, 105, and 120 min. (Error bars) Standard deviation of duplicate experiments. The details of this experiment are described in Materials and Methods.