Biopolymers · 1969 · 289 citations · 23 references
Life SciencesBiochemistryMolecular BiologyNucleic Acid BiochemistryNucleic Acid ChemistryPhysical ChemistryDna ChemistryNucleic Acid BiophysicsNucleic Acid StructureOligonucleotide ChemistryDna Base PairingDna Melting TemperatureIon Effects On Nucleic AcidsMelting Curve AnalysisMelting TemperatureMelting Temperature AnalysisNucleic Acid Hybridization ThermodynamicsOligonucleotide Thermodynamics
Abstract Equations were determined for the dependency of the melting temperature ( T m ) of DNA upon the logarithm of the sodium ion concentration, for four DNA samples of widely different base compositions (θ GC ). The slopes of these T m versus log M equations wore found to decrease with increasing θ G C of the samples. An empirical equation relating T m , log M (Na + ) and θ G C was derived, which also accounts for differences in T m versus log M slopes. Data from the literature for some synthetic polynucleotides and for the crab( Cancer pagarus ) satellite poly AT are discussed in relation to the above finding. The changes in T m versus log M slopes with θ G C are interpreted in terms of changes in the thermodynamic parameters Δ S and Δ H with base composition.
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