ProtoArray Human Protein Microarray version 3.0 enables screening of biological samples or of a labeled probe of interest against 5,000 unique human proteins in a single experiment. Full-length, native human proteins from a broad range of protein classes are arrayed in duplicate on nitrocellulose coated or modified glass slides. These high content arrays are utilized for identification of disease-specific protein biomarkers, mapping protein-protein interactions, antibody specificity profiling, and target discovery and validation.