Triple-labeling immunofluorescent staining patterns show RIIα, lipoic acid, and bungarotoxin separately and in composite overlay. RIIα immunoreactivity overlapped significantly with mitochondria, present along I-bands and in striations perpendicular to these bands. Within the muscle fibers, RIIα is seen to label the z-line, an area that phalloidin also labels (see fig. 1), in addition to the I-band. scale bar = 10 μm.