Molecular Biology Reports

, Volume 9, Issue 4, pp 223–226 | Cite as

Does the concentration of DNA (Co) and the time of incubation (t) as parameters of Cot influence the thermal stability of the DNA duplexes?

  • D. R. Bachvarov
  • I. G. Q. Ivanov
  • G. G. Markov


It has been shown in a previous paper (8) that the prime product of reassociation of related DNA sequences under open experimental conditions are mismatched duplexes which undergo ‘maturation’ upon further incubation. Due to this feature, the Tm value of the duplexes of a large number of DNAs is strongly dependent on the Cot value. Here we present data showing that the Tm of the duplexes of such type of DNAs depends also on the concentration of DNA in the range of one and the same Cot value. The significance of this finding in studying the taxonomic relationship by DNA-DNA hybridisation is discussed.


Thermal Stability Open Experimental Condition Taxonomic Relationship Mismatch Duplex 
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Co =

initial concentration of single-stranded DNA in moles of nucleotides per liter

t =

time of incubation in seconds

Cot =

the product of Co and t (mol. sec. 11)

PB =

an equimolar mixture of NaH2PO4 and Na2HPO4, pH 6.8



Ti =

incubation temperature

Tm =

melting temperature

Te =

elution temperature, i.e. the temperature at which one half of the DNA is eluted as single strands by HAP-thermal chromatography


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Copyright information

© Dr W. Junk Publishers 1984

Authors and Affiliations

  • D. R. Bachvarov
    • 1
  • I. G. Q. Ivanov
    • 1
  • G. G. Markov
    • 1
  1. 1.Institute of Molecular BiologyBulgarian Academy of SciencesSofiaBulgaria

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