While extending Serena's work to more difficult problems in the new lab at Upstate, we noticed one discrepancy. In Figure 4 (expt061017) she shows that the fully reduced form of TMPD has significant absorbance with a peak at about 590 nm. Now we find that dithionite completely bleaches any absorbance above ~370 nm (below which DT itself absorbs). Apparently we had a less pure sample of TMPD in Berkeley, and the contaminant shows its spectrum after TMPD is bleached by DT, and also in the very first spectrum after diluting TMPD into buffer, before auto-oxidation of TMPD to Wurster's blue swamps it out. Looking at the structure of the reduced form, one certainly wouldn't expect absorbance above 300 nm. This should have no effect on the results presented- We soon realized the deconvoluted values for TMPD(reduced) didn't make sense (we thought the spectrum was too small to be accurately extracted from the other components) and we based the oxidized/reduced ratio solely on the difference spectrum.