Three-dimensional atomic force microscopy image of raft microdomains. A binary mixture of 1,2-dioleoyl-sn-glycero-3-phosphocholine (black) and sphingomyelin (orange) forming a bilayer is immobilized on a mica substrate and exhibits a lipid phase separation. The height of the raft microdomains is ~7 Å. The yellow peaks correspond to a glycosylphosphatidylinositol-anchored protein which is located preferentially in the raft microdomains. The width of the scan is ~2 μm. Adapted from reference . Used with permission.