Ola Söderberg

My on-going research and future plans include both method development to provide better tools for investigating cell biology and application of these new methods in basic research and for improved diagnostics of e.g. cancer and infectious diseases. Since the development of the in situ proximity ligation assay (in situ PLA) (Söderberg et al., Nat Methods, 2006), most of our efforts have been related to the use of in situ PLA and to further improve the method, e.g. for multiplex analysis, simultaneous measurement of proteins and mRNA and for detection of protein-DNA interactions. In situ PLA combines multiple recognition of affinity reagents with potent signal amplification, utilizing methods for DNA analysis to generate a signal that will be a surrogate marker of the targeted protein, protein-protein interaction or post-translational modifications of proteins. The method is based on pairs of proximity-probes (i.e. antibodies conjugated to strands of DNA) to detect the proteins of interest. Only upon proximal binding of these probes can an amplifiable DNA molecule be generated by ligation, which enhance the selectivity of the method even further. We have also been working on developing novel methods, such as proximity-dependent initiation of hybridization chain reaction (proxHCR) (Koos et al., Nat Commun, 2015). ProxHCR retains the dual binding requirement of in situ PLA while not needing any enzymatic steps. Our ongoing work is focused on developing methods that will provide a deeper understanding on the biochemistry of the cell, and for analyses of DNA and RNA.