Fig. 7: Monomer buffering appears to be slower than nanotube growth for our selected concentrations of monomer buffering species.

a, b Mean seeded nanotube lengths measured in experiments (solid lines) or simulations (dashed lines) during buffer-regulated growth. Error bars represent 95% confidence intervals from bootstrapping. c, d S monomer concentrations during simulations of buffer-regulated growth (dashed lines). Solid lines represent the theoretical equilibrium S monomer concentrations over the course of the experiments (Supplementary Note 8). Regulated growth simulations were conducted as described in Supplementary Note 9 with [I_i]_o = [P_i]_o = 5.5 µM and [C_i]_o = 1.25 µM for both monomer types. The forward and reverse buffering rate constants were 1 × 10² and 1 × 10⁴ M⁻¹s⁻¹, respectively, for the simulations where monomer buffering was faster than growth (left panels) and 1 ×  10⁰ and 1 × 10² M⁻¹ s⁻¹ for the simulations where monomer buffering was slower than growth (right panels). See Supplementary Note 11 for additional simulation details.