DESCRIPTION: Phenotyping involves quantifying the vast array of molecular components that make up complex organisms. This proposal concerns nanobarcodes, a potentially revolutionary new technology platform for phenotyping. Nanobarcodes are free-standing, cylindrically-shaped colloidal metal nanoparticles, in which the metal composition can be alternated along the length, and in which the size of each metal segment can be controlled. Intrinsic differences in reflectivity between the metal segments allow individual particles to be visualized and identified by conventional optical microscopy. In contrast to conventional barcodes, nanobarcodes exist on biologically-relevant length scales can be functionalized to bind specifically to biomolecules, and can be interrogated in solution or on surfaces using conventional bioanalytical techniques, including fluorescence and mass spectrometry. As such, they offer unprecedented opportunities for assay miniaturization and assay multiplexing, the key obstacles to phenotypic analysis in small sample volumes. This grant focuses on two key feasibility issues based on four different types ("flavors") of nanobarcodes: (i) development of software for automated nanobarcode ID and fluorescence intensity detection; and (ii) demonstration of multiplexed immunoassays for mouse-specific proteins on nanobarcodes. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE