Pretargeting is an imaging strategy different from the imaging of traditional radiolabeled antibody, in which the antibody and radioisotope are administered in turn and then combined by coupling system within the body. Due to the high specificity and affinity between the coupling systems, the radioisotope is localized to the target in vivo, and then the radioactive labeling is achieved for imaging. Nuclear imaging using pretargeting methods can decrease the circulation duration of the radioisotope so as to reduce the uptake of the radioactivity in normal tissues, and facilitate the use of short-lived radioisotopes. This article provides a bird′s-eye view of 4 main strategies: biotin-streptavidin (SA) system, bispecific antibodies (BsAb) system, complementary oligonucleotides sequence, and bioorthogonal click chemistry system.

Radioimmunodetection; Isotope labeling; Antibodies; Trends