Abstract #1843

Artemov D, Zhu W, Okollie B, Bhujwalla Z

Avidin/streptavidin-biotin system is frequently used in pretargeting approaches to link antibody and targeting agent together due to the rapid reaction between avidin/streptavidin and biotin with high affinity. In the ideal pretargeting setting, cell membrane bound biotinylated antibody is tagged by avidin, which subsequently binds to a biotinylated functional agent. However, avidin is a tetramer that can bind to four biotinylated antibody molecules, which results in extensive cross-linking of the antibody before binding it to the funtional agents. We show here the internalization and recycling of Her-2/neu receptors induced by the above cross-linking and its application in MR signal enhancement.