Analytical ancestry: evolution of the array in analysis.

BACKGROUND Macro-, micro-, and nanosized arrays of test sites at various densities have emerged as important types of analytical devices in response to the need for high volume parallel analysis in both the research and the clinical laboratory. CONTENT This review explores the diversity of arrays of reaction vessels and arrays of reagents and of samples, with an emphasis on the earliest descriptions of the different variations. The scope of such arrays includes linear and 2-dimensional arrays of reaction vessels (e.g., microwell strips, microplates); linear and 2-dimensional arrays of reagents arrayed on pillars and posts; beads in wells; and reagents randomly arrayed (or dis-ordered) for use in next-generation sequencing. Micro- and nanofabrication technologies have been applied to the miniaturization of arrays to increase array density (e.g., DNA probe arrays) and produce arrays of analytical structures (e.g., cantilevers, nanoelectrospray nozzles). SUMMARY Arrays are now firmly established in many types of analytical devices, and this analytical format has gained widespread acceptance owing to the advantages of high-throughput automation and multiplex analysis. Ongoing "big biology" genomic and proteomic studies will ensure the continued dominance of array-based methods into the foreseeable future.