Fig. 4. Postsynaptic proteins are concentrated at synapses in AChRß^3F/3F mice. Frozen sections of hindlimb muscles from P30 wild-type and AChRß^3F/3F mice were stained with Alexa Fluor 594--BGT to label AChRs (red) and antibodies to APC, rapsyn, MuSK, Abl, utrophin, and dystroglycan (green). Each protein is concentrated at synapses in wild-type and AChRß^3F/3F mice. The image levels for AChRß^3F/3F mutant synapses were adjusted so that staining for AChR and other synaptic proteins was clearly visible. Scale bar: 20 µm.