Protein interaction refers to intentional physical contacts established between tow or more proteins as a result of biochemical events or electrostatic forces.
There are a multitude of methods to detect protein interaction. And the most widely used methods are yeast two-hybrid screening and affinity purification. Each of the approaches has its own strengths and weakness with regard to the sensitivity and specificity of the method, reliably validating these techniques presents a formidable challenge. For instance, the likelihood of non-specific artifacts be observed will be increased while applying the method of co-staining the interacting proteins with fluorescently antibodies.
Hybridization chain reaction (HCR) is another method that based on hybridization of DNA oligonucleotides to generate a signal, however it does not need ligation. In the latest researches, scientist have combined HCR with proximity-sensing in a new method for identifying protein interactions in situ both in fixed cells and in flow cytometry. “This antibody-based approach provides the benefits of PLA, and what’s better is that this method doesn’t require enzymatic steps.” Söderberg said, one of the researchers in the study.
To figure things out, this team included mismatches in the hairpins to reduce false positive signals. Moreover, they changed the length of the hairpin stem loop to optimize detection and stability. With this novel approach, those scientists were able to visualize numerous protein interactions.
“We have to admit, for the analysis of live samples, methods like FRET and PCA have advantages over our methods. But we will try our best to improve this new method so that it could also function under these conditions. I think, though, that our method will mainly be used for diagnostic purpose.” commented Söderberg.