Figure 5

PCA analysis of spiked and not-spiked healthy urine. (a) Plot of the sample scores for PC1 and PC2 obtained from PCA analysis of the replicate analysis of a healthy volunteer's urine sample spiked (open triangle) or not (black circle) with calibrator peptides (Human angiotensin II (1046.54 Da 1X = 120 fmol/μl), neurotensin (1672.91 Da, 1X = 80 fmol/μl) and ACTH 18–39 fragment (2465.19 Da, 1X = 100 fmol/μl)). (b) Plot of the loadings for PC1 and PC2 for spiked and non-spiked samples (spiked peptide loadings are circled).