The number of proteins that constitute the human proteome is quite large. Many efforts are underway to examine the human proteome, and the protein complements in other species, as well. To assist in this effort there is a wide variety of bioinformatics tools and databases available for the analysis of proteins. Protein Microarrays, consist of antibodies, proteins, protein fragments, peptides, aptamers or carbohydrate elements that are immobilized in a grid-like pattern on a glass surface. The arrayed molecules are then used to screen and assess protein interaction patterns with samples containing distinct proteins or classes of proteins. Protein Amino Acid Sequences, the analysis of amino acid sequences, or primary structure, of proteins provides the foundation for many other types of protein studies. The primary structure ultimately determines how proteins fold into functional 3D structures. Primary structure is used in multiple sequence alignment studies to determine the evolutionary relationships between proteins, and to determine relationships between structure & function in related proteins.