Practice question

Immunoprecipitation captures native protein complexes using antigen-antibody interaction. Specific antibody against bait protein is immobilized on Protein A/G beads, precipitating bait along with associated partners from lysate for subsequent immunoblotting or mass spectrometry. Success depends entirely on availability of high-affinity, specific antibody that recognizes native epitope without cross-reactivity. Lack of suitable antibody, epitope masking by interactors, or interference from heavy chains limits utility. The method does not need electrical fields, high temperature, or inherently toxic components; antibody quality remains critical bottleneck.