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THE distributions of dystrophin, `dystrophin-related protein' (DRP) and β-spectrin were compared with that of acetylcholine receptors (AChRs) at rat nerve-muscle junctions (NMJs) using immunofluorescence techniques. In sections, monoclonal antibodies (MAbs) to dystrophin and β-spectrin labelled the entire sarcolemma but were concentrated at the NMJs while those to DRP labelled only NMJs. In permeabilized muscle fibres, DRP was precisely co-localized with the AChRs, whereas the zone of high density labelling of dystrophin and β-spectrin extended 0.3–0.4 μm beyond the AChRs. Within the NMJ, the labelling of DRP appeared as a series of interconnecting lines similar to that of AChRs. However, labelling of dystrophin and β-spectrin was consistently more punctate. These data suggest DRP is more closely associated with AChRs than are dystrophin or β-spectrin.