radioactive cyanocobalamin

ra·di·o·ac·tive cy·a·no·co·bal·a·min

cyano[57Co]cobalamin, cyano[58Co]cobalamin, or cyano[60Co]cobalamin produced by the growth of particular microorganisms on a medium containing cobalt 57, cobalt 58, or cobalt 60; used in the investigation of the absorption and metabolism of cyanocobalamin (vitamin B12).