title: [Thermal denaturation of DNA in concentrated salt-free solutions: comparison of microcalorimetric and spectrophotometric data].
abstract: Scanning microcalorimetry and spectrophotometry were used to study the dependence of melting enthalpy (delta Hm) and temperature (Tm) on DNA concentration in salt free solutions and on NaCl concentration in solutions with constant DNA concentration. This data is used to calculate the Manning's charge density parameter which is found to be equal 1.8. The linear dependence of Tm on the logarithm of DNA concentration in salt free solution was obtained. An approximate evaluation of dissociation degree in native DNA at different concentrations was made by comparison of straight lines in the Tm = f(lg CNaCl) and Tm = f(lg Cp) coordinates.
mesh_terms: D000818:Animals; D002152:Calorimetry, Differential Scanning; D002645:Chickens; D004247:DNA; D004912:Erythrocytes; D006358:Hot Temperature; D009691:Nucleic Acid Denaturation / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology; D012996:Solutions; D013053:Spectrophotometry; D013816:Thermodynamics
chemical_list: D012996:Solutions; D012965:Sodium Chloride; D004247:DNA
vernacular_title: Termicheskaia denaturatsiia DNK v kontsentrirovannykh bessolevykh rastvorakh: sopostavlenie mikrokalorimetricheskikh i spektrofotometricheskikh dannykh.