SIGMA A6792-1ML

Second antibodies (secondary antibodies) are antibodies raised against other antibodies, typically from another species, called primary antibodies. Primary antibodies are generated with and bind to specific antigens to create antigen antibody complexes which may be detected in a variety of immunochemical and immunohistochemical configurations involving soluble or insoluble signaling molecules. The immunodetection system depends upon the binding of a signal competent secondary antibody to a primary antibody:antigen complex. The suitability of any secondary antibody to a specific immunodetection application is dependent upon its signal development system configuration. Signal development systems are based upon the chemical conjugation of a signal mediator to the secondary antibody. Major secondary antibody signal systems are color (chromogenic), chemiluminescence or fluorescence based and involve the use of enzymes or high affinity binary systems such as biotin:avidin. Horseradish Peroxidase (HRP) is an enzyme that catalyzes the conversion of chromogenic substrates such as o-phenylenediamine (OPD), 4-chloro-1-naphthol 3,3’,5,5’-tetramethylbenzidine (TMB), 3,3'-Diaminobenzidine (DAB) or 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS); chemiluminescent substrates such as CPS-3 (enhanced luminal) and fluorogenic substrates such as Ampliflu™ Red into detectable chromophores, light-emitters or fluorescers, respectively.