The aim of this thesis was to develop methods for peptide based bead arrays for validation of peptide biomarker candidates. In previous projects autoantibody signatures for colorectal cancer diagnostic were identified. The derived peptides of the protein antigens were selected on high density peptide arrays as biomarkers for differentiating between carcinoma and adenoma patients (polyps) as well as healthy probands. In this thesis a peptide coupling protocol based on click chemistry was successfully established. The analysis protocol was also improved by minimising the background signal. With the final protocols, the analytical performance of the bead-assay was defined. Both the limit of detection and quantification were on average at 0.0063 mg/ml IgG, which allows for highly sensitive analytics. Furthermore, a 192-plex assay with these methods resulted in a highly dynamic measuring range; the coefficient of determination for an IgG dilution series was above 0.9 for 97% of the tests. Finally, 22 clinical plasma samples (6 controls, 8 polyps, 8 carcinomas) were tested with a 192-plex peptide array. The class comparison showed only a few significant peptides (n=2 control vs. carcinoma; n=3 polyp vs. carcinoma) with different reactivities. The established protocols of this thesis are a valuable foundation for future development of peptide-based multiplex tests for autoantibody diagnostics.