DNA microarray

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An orderly arrangement of DNA sequences on a small solid support, usually a membrane or glass slide, used to quickly survey the simultaneous expression of many genes.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun a collection of microscopic DNA spots attached to a solid surface forming an array; used to measure the expression levels of large numbers of genes simultaneously