Analysis of Protein Interactions in Patient-Derived Xenografts Using Immunoprecipitation

Proteins are large, complex molecules that regulate multiple functions within the cell. The protein rarely functions as a single molecule, but rather interacts with one or more other proteins forming a dynamic network. Protein–protein interactions are critical for regulating the cell’s response toward various stimuli from outside and inside the cell. Identification of protein–protein interactions enhanced our understanding of various biological processes in the living cell. Immunoprecipitation (IP) has been one of the standard and most commonly used biochemical methods to identify and confirm protein–protein interactions. IP uses a target protein-specific antibody conjugated with protein A/G affinity beads to identify molecules interacting with the target protein. Here, we describe the principle, procedure and challenges of the IP assay.