4,4'-[9H-Carbazole-3,6-diyldi-(1E)-2,1-ethenediyl]bis[1-methyl-pyridinium Diiodide-d6 is the isotope labelled analog of 4,4'-[9H-Carbazole-3,6-diyldi-(1E)-2,1-ethenediyl]bis[1-methyl-pyridinium Diiodide (C176070); a good human quadruplex DNA stabilizer and telomerase inhibitor.