α-Bungarotoxin, a 74—amino acid peptide extracted from Bungarus multicinctus venom, binds with high affinity to the α-subunit of the nicotinic acetylcholine receptor (AChR) of neuromuscular junctions. Our bright and photostable Alexa Fluor 594 α-bungarotoxin may prove to be one of the best probes for visualizing this receptor. Fluorescent α-bungarotoxin conjugates can be used to facilitate identification of nicotinic AChRs and to localize neuromuscular junctions.