Fig. 3

Characterisation of IC formation by QCM-D. Time-resolved changes in (A) ΔF (frequency change proportional to surface mass) and (B) ΔD (dissipation change proportional to viscoelastic properties) during IC formation with mAbs 11D2, 12F8, 4E12 and 5H10. n—number of measured overtones of oscillating quartz crystal. ΔD/ΔF plots obtained by plotting ΔF on the x-axis and ΔD on the y-axis and eliminating time as an explicit parameter for antigen (Ag) VLPs (C) and for mAbs of different clones 11D2, 12F8, 4E12 and 5H10 (D). (C) VLPs were covalently immobilized on the gold surface for each mAb (clones 11D2, 12F8, 4E12 and 5H10) and ΔD/ΔF plots for separate VLP immobilization are shown. D The slopes were calculated from fitted lines of ΔD/ΔF plots for mAbs. If ΔD/ΔF plot is non-linear (more than 1 slope) it indicates conformational changes on the layer during VLP-mAb interaction. From fitted lines the slopes were calculated (D). E Schematic representation of formed IC layer characteristics. ΔF values represent the changes in surface mass of mAbs bound to VLPs (Ag). E was created with BioRender.com, AG No.: AV268OTFM3