The molecule is a double-stranded DNA polynucleotide consisting of two complementary strands consisting of repeating units of brominated guanosine and deoxycytidine residues, all residues in each strand being connected by 3'->5' phosphodiester linkages. The sites of bromination are at C-8 of guanine and C-5 of cytosine, although not all these sites are brominated, with bromination at the guanine C-8 predominating. It contains a brominated poly[d(GC)].
[(2R,3S,5R)-5-(2-amino-8-bromo-6-oxo-1H-purin-9-yl)-2-(phosphonooxymethyl)oxolan-3-yl] [(2R,3S,5R)-5-(4-amino-5-bromo-2-oxopyrimidin-1-yl)-3-hydroxyoxolan-2-yl]methyl hydrogen phosphate