Genome Technology Center

Digitizing Interactome Dynamics

Localized in situ quantification of protein interactions and modifications in cells and tissue by proximity ligation.

Simon Fredriksson, CSO, Olink Bioscience


A unique technology has been developed for quantification of endogenous protein expression, modifications and interactions in fixed cells and tissue (Jarvius et al Mol Cell Proteomics 2007 6(9)1500-9). This proximity ligation based protocol enables the detection of antibody pairs within a ~40 nm distance providing a localized and rolling circle amplified signal. Pairs of primary standard immuno histochemistry antibodies are used for the specific recognition of the target molecule or molecules. Secondary antibodies equipped with oligonucleotides then bind to the primary ones and subsequently by ligation generate a circular amplicon if these are in close proximity. Quantification is enabled by single molecule counting of each distinct amplification product at their respective location in the cells. Some applied examples presented will be Her2 interactions with EGFR or Her3 in breast cancer, the TGF-beta signaling pathway and SMAD interactions, and PDGF-receptor phosphorylation.


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