Practice question

Ideal interaction analysis provides association rate, dissociation rate, and equilibrium dissociation without labeling proteins, avoiding artefacts from fluorophores or radioisotopes and enabling kinetic quantification. Surface Plasmon Resonance achieves this by optical detection of refractive index changes upon analyte-ligand binding on gold sensor chip. It operates continuously, generating sensorgrams in real-time with high sensitivity. EMSA requires labeled nucleic acid, FRET needs fluorescent fusions, BiFC relies on split fluorescent protein complementation. SPR therefore provides unbiased, label-free quantification of protein-protein binding specificity and affinity in real-time.