Absolute absorbance readings (not normalized) are shown for (a-f) A600 and (g) A280. Reference data (◆ and () in graphs (a-f) and (g), respectively), data after a Δtcool of 1 day (), 4 days (), 7 days (), 14 days (), 21 days (), 28 days (). All the runs have been shifted to the right by text = 1.5 hours. Fits of the data, using Eq. (2) () and Eq. (3) (), are displayed in the graphs (a-f) showing good agreement with the experimental data. Goodness-of-fit are given in the legend of Fig. S1. (g) The initial insulin concentration for all the samples (prepared from the same batch) was ∼2 mg/ml. The following linear calibration curve was used in the range 0.0-2.0 mg/ml of dissolved insulin: A280 = 0.810 · c, (R2=0.999).