Antigen
Antigens are "targeted" by antibodies. Each antibody is specifically produced by the immune system to match an antigen after cells in the immune system come into "contact" with it; this allows a precise identification or matching of the antigen and the initiation of a tailored response. The antibody is said to "match" the antigen in the sense that it can bind to it due to an adaptation in a region of the antibody; because of this, many different antibodies are produced, each able to bind a different antigen while sharing the same basic structure. In most cases, an adapted antibody can only react to and bind one specific antigen; in some instances, however, antibodies may cross-react and bind more than one antigen.
Anti-dsDNA antibodies
Microarrays are a newly emerging method for the detection of ANA. Individual autoantigens are deposited in an array of dots onto a surface such as polystyrene. A single array could consist of hundreds of autoantigens for screening of multiple autoimmune diseases simultaneously. If anti-dsDNA antibodies are present, incubation of serum and the microarray allow for binding and the dots can then be visualised using a fluorescent labelled anti-IgG antibody.