These antibodies are typically detected with chemiluminescent, fluorescent or colorimetric assays. Detection by chemiluminescent substrates has several advantages over chromogenic substrates. Stripping filters are much easier when chemiluminescent substrates are used. Detection is typically performed using peroxidase linked antibodies to catalyse a chemiluminescent reaction. Nitric oxide concentration can be determined using a chemiluminescent reaction involving ozone. Blue Devil Film is used for blotting, sequencing, chemiluminescent autoradiography (ecl) and gel shift analysis. It displays strong fluorescence and is used as a chemiluminescent fluorophore with high quantum efficiency. After antibody binding, the membrane is incubated with a chemiluminescent substrate and imaged. In a chemiluminescent reaction, the direct product of the reaction is an excited electronic state. When a chemiluminescent substrate is exposed to the enzyme it allows detection. It is used as a probe for superoxide anion in biology, for its chemiluminescent properties.