The proposed project will develop a novel diagnostic reagent that detects cancer-associated cell surface proteins. Specifically, a bioactive peptide that can bind to the cell surface proteins will be displayed on the synthetic chromatin and examined its selective binding affinity to cancer cells. To this end, recombinant proteins will be purified from E. coli and the synthetic chromatin will be assembled by a self-assembly process. The synthetic chromatin will be validated by cell-based binding assays using breast cancer cells.