Fig. 7. TEM of the IE–endothelial-cell interaction in K⁺ and K^– IEs. (A) Low-power micrograph of a K⁺ IE (P) that is adhering to the surface of an endothelial cell (En). Bar, 1 µm. (B) Detail of the interface between a K⁺ IE and an endotheial cell showing strands of connecting material specifically located at knobs (arrows). Note the presence of a Maurer's Cleft (M). Bar, 100 nm. (C) Interface between a K^– IE and an endothelial cell in which individual clumps of electron dense material can be seen forming connections between the plasma membranes of the IE and endothelial cell (arrows). Bar, 100 nm.