| abstract |
PROBLEM TO BE SOLVED: To combine a ligand, a spacer and a peptide linker useful for an in-vivo diagnostic agent and an internal radiotherapy using an anti-human CEACAM5 antibody Fab fragment whose binding activity is not attenuated by labeling with a metal, a fluorescent dye or the like. Body provision. A complex comprising an anti-human CEACAM5 antibody Fab fragment and a ligand comprising a heavy chain fragment comprising a heavy chain variable region consisting of a specific amino acid sequence and a light chain containing a light chain variable region consisting of a specific amino acid sequence. The complex consisting of a body or a ligand, a spacer, and a peptide linker can be used as a diagnostic composition and / or a pharmaceutical composition without diminishing the binding activity even by labeling with a metal, a fluorescent dye, or the like. [Selection diagram] None |