Isolation of a Nav channel blocking polypeptide from Cyanea capillata medusae - A neurotoxin contained in fishing tentacle isorhizas

► Neuroblastoma cell assay-guided venom purification. ► LMPC combined MALDI TOF MS for biochemical analysis of nematocysts. ► Novel sodium channel blocking 8.22-kDa polypeptide from C. capillata. ► Detection of the isolated neurotoxin in tentacle isorhizas.