Biotinylation of Antibodies

The high affinity and specificity of the avidin-biotin interaction permit diverse applications in immunology, histochemistry, in situ hybridizations, affinity chromatography, and many other areas (1 ) (see Chapter 21 and Chapter 22 ). It was first exploited in immunocytochemical applications in the mid-1970s (2 ,3 ), and has since been commonly used to localize antigens in cells and tissues. In this technique, a biotinylated primary or secondary antibody is first applied to the sample, and the detection is accomplished by using labeled avidin. Avidin with a variety of labels are available commercially, including fluorescent, enzyme, iodine, ferritin, or gold labels.