可用来作为特殊的功能标准进行测试的生物材料，在小空间有址可寻的排列在惰性材料上。生物材料可以是用于与已知序列的DNA和RNA杂交的DNA片段；或可用来分析并得到结构/功能信息的蛋白质或多肽。其它微点阵的用途包括从大量分子中筛选出能结合特定靶蛋白的分子。微点阵技术需要一个荧光、辐射或彩色读出的测试步骤，具有一定分辨率的扫描仪对点阵表面的每一个有址可寻的点进行分析。微点阵最大的优点是能同时识别大量分子，而这些分子只需少量。（少至每个点一个分子）。DNA微点阵（DNA芯片）常规用于有治疗或经济价值的基因功能、表达和变异的研究，而蛋白芯片用于研究蛋白组学应用和蛋白--蛋白通道。小分子微辐射被用于大的组合文库的超高度大规模筛选。

Small, spatially addressable arrays of biological material (on an inert substrate) that can be tested for specific functional criteria. The biological material could be DNA fragments probed for hybridization to a known sequence of DNA or RNA (useful for sequencing, expression studies, diagnostics); or proteins or peptides which can be analyzed to obtain structure/function information. Other uses of microarrays include the screening of large numbers of molecules for their capacity to bind a particular target protein. Microarray technology requires the testing or probing procedure to be “reported” by a fluorescent, radioactive or color readout, which can be analyzed by scanners with a resolution equivalent to each addressable point on the array surface. The greatest advantage of microarrays is their ability to simultaneously address large numbers of molecules - and that the molecules need only be present in small quantities (as few as a single molecule per array point). DNA microarrays (“DNA chips”) are being routinely used to probe the function, expression and variations in genes of therapeutic or economic interest, and protein chips are becoming available for studying proteomics applications and protein-protein pathways. Small molecule microarrays are being used in ultra high throughput screening of large combinatorial libraries (see microfluidics).