The binding of tritiated tetrodotoxin to squid giant axons

Abstract
The binding of tetrodotoxin to squid giant axons was determined as a function of toxin concentration, using a tritiated toxin preparation of known radiochemical purity and specific activity. From the amount of saturable binding observed, the number of toxin binding sites thought to be sodium channels was found to be 553 ± 119/p.m 2 of axon surface.