A method is described where the aminoacyl-tRNA synthetase system is used to create very small devices for quantitative analysis of the amino acids that occur in proteins. The basis of the method is that each of the 20 synthetases and/or a tRNA specific for a different amino acid is separated spatially (e.g. in tiny chambers or on a surface). The reactions catalyzed by all 20 synthetases are monitored in a spatially resolved manner. Each separately positioned synthetase or tRNA will signal its cognate amino acid. The synthetase reactions can be monitored using continuous spectroscopic assays. Alternatively, since elongation factor Tu;GTP (EF-Tu;GTP) specifically binds all AA-tRNAs, the aminoacylation reactions catalyzed by the synthetases can be monitored using ligand assays. Microarrays for amino acid analysis are suggested. Additionally, it is possible that amino acid analysis arrays can be integrated with aminopeptidase or carboxypeptidase digestions to produce miniaturized enzymatic sequenators capable of generating either N- or C-terminal sequence data at femtomole-attomole levels. The possibility of parallel processing of many samples in an automated manner is discussed.