Proximity-dependent initiation of hybridization chain reaction

Nat Commun. 2015 Jun 12;6:7294. doi: 10.1038/ncomms8294.


Sensitive detection of protein interactions and post-translational modifications of native proteins is a challenge for research and diagnostic purposes. A method for this, which could be used in point-of-care devices and high-throughput screening, should be reliable, cost effective and robust. To achieve this, here we design a method (proxHCR) that combines the need for proximal binding with hybridization chain reaction (HCR) for signal amplification. When two oligonucleotide hairpins conjugated to antibodies bind in close proximity, they can be activated to reveal an initiator sequence. This starts a chain reaction of hybridization events between a pair of fluorophore-labelled oligonucleotide hairpins, generating a fluorescent product. In conclusion, we show the applicability of the proxHCR method for the detection of protein interactions and posttranslational modifications in microscopy and flow cytometry. As no enzymes are needed, proxHCR may be an inexpensive and robust alternative to proximity ligation assays.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Epidermal Growth Factor / chemistry
  • ErbB Receptors / chemistry
  • Flow Cytometry
  • Fluorescent Dyes / chemistry
  • Nucleic Acid Hybridization*
  • Oligonucleotides / chemistry*
  • Protein Binding


  • Fluorescent Dyes
  • Oligonucleotides
  • Epidermal Growth Factor
  • ErbB Receptors