title: Terbium as a new probe to detect G+C content of DNA.
abstract: Tb3+ has been tested as a probe to determine G + C per cent composition of DNA. DAPI, a fluorescent dye specific for A + T bases, has been employed at the same time as a complementary probe. Using calf thymus DNA (G + C = 40%; A + T = 60%), it has been found that the binding of the two dyes is independent, and that one binding site every 12,5 nucleotides exists for Tb3+ and one binding site every 8.3 nucleotides for DAPI. The simultaneous use of Tb3+ and DAPI allows therefore the monitoring of A-T, G-C sequences.
mesh_terms: D000818:Animals; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D003596:Cytosine / Q000032:analysis*; D004247:DNA; D006147:Guanine / Q000032:analysis*; D007700:Kinetics; D013050:Spectrometry, Fluorescence / Q000379:methods; D013725:Terbium; D013950:Thymus Gland
chemical_list: D013725:Terbium; D006147:Guanine; D003596:Cytosine; D004247:DNA