Genetic identity. Conceptual computer artwork of a hand and a DNA microarray, representing genetic identity. A DNA (deoxyribonucleic acid) microarray is used to study thousands of genes at once. It is used to link genetic samples with known genes. The genetic samples are given fluorescent labels. The microarray is a large array of possible genes used to test the samples. If any of the samples match genes in the array, they bind to that site to form these coloured dots. The pattern of colours is then analysed. Microarrays can be used to study gene expression or detect mutations. The technique is also used in proteomics, the study of proteins.