Using wheat germ agglutinin (WGA) to verify differential distribution patterns of Na V 1.5 inside myocytes and on myocyte surface. CON and PKA myocytes (incubation time 15 h) were stained for native NaV1.5 (green) and WGA (red). Z-stack images at 50-nm z steps were collected. Shown are images of NaV1.5, WGA, and their merge at z planes deep inside myocytes (purely inside), and at the interface between surface and subsarcolemmal space (mixed). In the latter, the surface areas are demarcated by dashed white lines. In the “purely inside” views, both NaV1.5 and WGA are in striations of ∼2 µm spacing, and along the lateral cell edge. There are WGA-positive vesicles. In the “mixed” views, NaV1.5 and WGA are in faint striations in the subsarcolemmal space. However, WGA manifests a vague hexagonal pattern while NaV1.5 is in random clusters on the surface. NaV1.5 clusters are much denser on the surface of PKA than CON myocytes.
