Metabolic biotinylation of cell surface receptors for in vivo imaging

Nat Methods. 2006 May;3(5):391-6. doi: 10.1038/nmeth875.


We have developed a versatile, potent technique for imaging cells in culture and in vivo by expressing a metabolically biotinylated cell-surface receptor and visualizing it with labeled streptavidin moieties. The recombinant reporter protein, which incorporates a biotin acceptor peptide (BAP) between an N-terminal signal sequence and a transmembrane domain, (BAP-TM) was efficiently biotinylated by endogenous biotin ligase in mammalian cells with the biotin displayed on the cell surface. Tumors expressing the BAP-TM have high sensitivity for magnetic resonance and fluorescence tomographic imaging in vivo after intravascular injection of streptavidin conjugated to magnetic nanoparticles or fluorochromes, respectively. Moreover, streptavidin-horseradish peroxidase conjugates in conjunction with a peroxidase-sensitive gadolinium agent further increased and prolonged the magnetic resonance signal. This BAP-TM allows noninvasive real-time imaging of any cell type transduced to express this reporter protein in culture or in vivo.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Biosensing Techniques / methods*
  • Biotin / metabolism*
  • Biotinylation*
  • Cell Membrane / metabolism
  • Cells, Cultured
  • Genes, Reporter
  • Green Fluorescent Proteins / analysis
  • Humans
  • Magnetic Resonance Imaging / methods
  • Microscopy, Fluorescence / methods
  • Peptides / chemistry
  • Receptors, Cell Surface / chemistry
  • Receptors, Cell Surface / metabolism*
  • Streptavidin / chemistry
  • Transduction, Genetic


  • Peptides
  • Receptors, Cell Surface
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • Biotin
  • Streptavidin