Measurement of peptide dissociation from MHC class II molecules

This unit describes a method of measuring the kinetic stability of complexes formed between purified MHC class II molecules and antigenic N-terminal fluorescein-labeled peptides. An HPLC-SEC allows for the separation of fluoresceinated MHC class II:peptide complexes from excess free dissociating peptides, while the fluorescence detector allows for the quantification of the remaining complexes throughout the dissociation time-course.