Methods for detecting protein-protein interactions

Protein-protein interaction (PPI) is central to all cellular processes and play critical roles in both normal physiology and disease pathogenesis. In this brief guide, we outline the fundamental principles and widely used methods for PPI detection, focusing on 3 key techniques: immunoprecipitation, in vitro pull-down assays, and proximity ligation assay. We also discuss common experimental challenges and provide practical optimization strategies to improve reliability and reproducibility. This resource is designed to aid researchers in molecular and cellular biology, signal transduction, and animal model studies with essential knowledge for selecting and applying PPI detection methods.