Fig. 3.

SEM analysis of the SPR-chip surface. a Control sample in absence of added ApoE to probe for non-specific binding where the immobilized fibrils on the SPR-chip have been sequentially probed with anti-ApoE antibodies and protein-A conjugated 15 nm gold-beads. b Complete setup where fibrils bound to the SPR-chip have been sequentially probed with ApoE4, anti-ApoE antibodies and protein-A conjugated 15 nm gold-beads. Scale bar is 100 nm