Figure 3: (A) The observed relative abundances (denoted Theta1) for the peptides that matched to Bovine serum albumin, relative to their estimated incorporation rate. (B) The observed relative abundances (denoted Theta1) for peptides that matched to Human transferrin, relative to their estimated incorporation rate. A vertical reference line at Theta1=0.5 and a density curve are included in both figures; a density curve is a smooth curve fit on the distribution of relative abundance values that represents the proportion of species that have the corresponding relative abundance.