Protein detection using proximity-dependent DNA ligation assays

Nat Biotechnol. 2002 May;20(5):473-7. doi: 10.1038/nbt0502-473.


The advent of in vitro DNA amplification has enabled rapid acquisition of genomic information. We present here an analogous technique for protein detection, in which the coordinated and proximal binding of a target protein by two DNA aptamers promotes ligation of oligonucleotides linked to each aptamer affinity probe. The ligation of two such proximity probes gives rise to an amplifiable DNA sequence that reflects the identity and amount of the target protein. This proximity ligation assay detects zeptomole (40 x 10(-21) mol) amounts of the cytokine platelet-derived growth factor (PDGF) without washes or separations, and the mechanism can be generalized to other forms of protein analysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Becaplermin
  • Chemistry, Clinical / methods*
  • DNA / metabolism*
  • Dose-Response Relationship, Drug
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Molecular Sequence Data
  • Oligonucleotides / metabolism*
  • Platelet-Derived Growth Factor / analysis*
  • Platelet-Derived Growth Factor / pharmacology
  • Proteins / analysis*
  • Proto-Oncogene Proteins c-sis
  • Sensitivity and Specificity
  • Thrombin / pharmacology
  • Time Factors


  • Oligonucleotides
  • Platelet-Derived Growth Factor
  • Proteins
  • Proto-Oncogene Proteins c-sis
  • Becaplermin
  • DNA
  • Thrombin