Increasing the specificity and function of DNA microarrays by processing arrays at different stringencies

DNA microarrays have for a decade been the only platform for genome-wide analysis and have provided a wealth of information about living organisms. DNA microarrays are processed today under one condition only, which puts large demands on assay development because all probes on the array need to function optimally under one condition only. Microarrays are often burdened with a significant degree of cross-hybridization, because of a poor combination of assay conditions and probe choice. As reviewed here, a number of promising microfluidics-based technologies can provide automatic processing of arrays under different assay conditions. These new array processors provide researchers and assay developers with novel possibilities to construct highly specific DNA arrays even towards regions of DNA greatly varying in G?+?C content. These array processors are also a powerful development tool for building arrays, because they combine high sample throughput with investigation of optimal assay conditions. The array processors can increase specificity in all DNA microarray assays, e.g. for gene expression, and microRNA and mutation analysis. Increased specificity of the array will also benefit microarray-based loci selection prior to high-throughput sequencing.