<chemical> 3,8-diamino-5-(3-(diethymethyammonio) propyl)-6-phenylphenanthridium. Quaternary ammonium analog of ethidium; an intercalating dye with a specific affinity to certain forms of DNA and, used as diiodide, to separate them in density gradients; also forms fluorescent complexes with cholinesterase which it inhibits. ... Pharmacological...