Figure 1: Data handling workflow using the three different strategies. Data handling for high resolution serum peptide profiles started with sample processing, followed by profile processing and data processing. During profile processing, the three methods for data handling were used to analyze the same high resolution serum peptide profiles. The methods: Method 1, the full serum peptide profile is analyzed; Method 2, R script to remove all datapoints except those within the 42 selected peptide isotope clusters at +0.5< m/z selected monoisotopic peak < 3.5; Method 3, all datapoints are removed except for 139 selected peaks of which the intensity of each peak is integrated and calculated using Xtractor.