Development of new biotin/streptavidin reagents for pretargeting

The high affinity of biotin for streptavidin has made this pair of molecule s very useful for in vivo applications. To optimize reagents for one potent ial in vivo application, antibody-based pretargeting of cancer, we have pre pared a number of new biotin and streptavidin derivatives. The derivatives developed include new radiolabeled biotin reagents, new protein biotinylati on reagents, and new biotin multimers for cross-linking and/or polymerizati on of streptavidin. We have also modified streptavidin by site-directed mut ation and chemical modification to improve its in vivo characteristics, and have developed new reagents for cross-linking antibody fragments with stre ptavidin. A brief overview of these new reagents is provided. (C) 1999 Else vier Science B.V. All rights reserved.