可用來作為特殊的功能標準進行測試的生物材料，在小空間有址可尋的排列在惰性材料上。生物材料可以是用于與已知序列的DNA和RNA雜交的DNA片段；或可用來分析并得到結構/功能信息的蛋白質或多肽。其它微點陣的用途包括從大量分子中篩選出能結合特定靶蛋白的分子。微點陣技術需要一個熒光、輻射或彩色讀出的測試步驟，具有一定分辨率的掃描儀對點陣表面的每一個有址可尋的點進行分析。微點陣最大的優點是能同時識別大量分子，而這些分子只需少量。（少至每個點一個分子）。DNA微點陣（DNA芯片）常規用于有治療或經濟價值的基因功能、表達和變異的研究，而蛋白芯片用于研究蛋白組學應用和蛋白--蛋白通道。小分子微輻射被用于大的組合文庫的超高度大規模篩選。

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).