Figure 4. AFM contact mode images in PBS of DOPC/DPPC model supported lipid bilayers and their interactions with human Aβ peptide. (A) Supported bilayer made from DOPC to DPPC in a molar ratio of 3:1. Typical phase separation is observed with the DPPC gel phase islands (example indicated by the blue arrow) surrounded by the liquid disordered DOPC phase (example indicated by the black arrow). (B) Proposed origin of height difference of the gel phase relative to liquid disordered phase. (C) DOPC/DPPC bilayer after exposure for 2 hours to 8 μM of human Aβ. The Aβ has adsorbed exclusively onto the DOPC liquid disordered phase, the DPPC gel phase remaining untouched. (D) A zoom in of the area enclosed in the circle in (C)., the Aβ being seen to avoid the DPPC gel domains, even the small central DPPC gel domain remaining untouched.