Figure 8
From: Precise protein quantification based on peptide quantification using iTRAQ™
Quantification results of the protein BGAL_ECOLI (P00722). Samples were mixed in a ratio of 1:3. The sequence of the outlying peptide 7 is APLDNDIGVSEATR with a ratio of 1.5171 ± 0.0121. Figure a) shows the standard boxplot of the peptide ratios. The median is 0.9674. Outliers are marked in red. They not distort the calculation of the protein ratio. Figure b) depicts the protein ratio calculated by the LSE value of the single peptide ratios, 0.9936. The red line indicates the LSE value, i.e. the protein ratio calculated from the relative peptide abundances. The blue crosses mark the corresponding errors of each peptide ratio, the red ones the peptide ratios.