Fig. 3

Box plots of the distribution of IS corrected peak areas derived from LS-MS/MS measurement of the ApoE peptides necessary for proteotyping. The p-value from a Welch’s t-test comparing the positive and negative peak area distributions is inset. No samples without LAVYQAGAR peptide were found in this investigation. As indicated by the p-value and box plots, there was a large discrepancy between signals assigned as positive and negative enabling differentiation. Box plots represent medians and quartiles with whiskers extending across the result distribution