Nature Communications 2015-01-01

Proximity-dependent initiation of hybridization chain reaction.

Björn Koos, Gaëlle Cane, Karin Grannas, Liza Löf, Linda Arngården, Johan Heldin, Carl-Magnus Clausson, Axel Klaesson, M Karoliina Hirvonen, Felipe M S de Oliveira, Vladimir O Talibov, Nhan T Pham, Manfred Auer, U Helena Danielson, Johannes Haybaeck, Masood Kamali-Moghaddam, Ola Söderberg

Index: Nat. Commun. 6 , 7294, (2015)

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Abstract

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.