In-depth characterization and computational 3D reconstruction of flagellar filament protein layer structure based on in situ spectroscopic ellipsometry measurements

► Flagellar filaments were immobilized onto Ta2O5 substrates in flow-cell. ► The surface was monitored in situ with spectroscopic ellipsometry. ► New optical model was developed for the characterization of the filamentous layers. ► The depth profile of protein mass density was determined. ► The statistical 3D structure of the filamentous layer was reconstructed.