DNA melting temperature

Fig. 4 Dependence of DNA melting temperature Tm on duplex length N. (a) Experimental data from [6], obtained for [Na+] = 1 M. The saturation is already approached for N = 35. (b) Calculated behavior for the same conditions of (a), based on NN parameters. Reproduced with permission from [8]...

Parameters such as liposome size, charge, Dave and and fluidity have little effect on the Liu DNA melting temperature. Cryo- [168]... 

Fig. 9. The variation of DNA melting temperature as a function of metal ion concentration. (From Ref. 27.)...

FIGURE 12.17 Heat denaturation of DNA from varions sources, so-called melting curves. The midpoint of the melting curve Is defined as the melting temperature, T . (From Marmur, J., 1959. Nature 183 1427-1429.)... 

FIGURE 12.18 The dependence of melting temperature on relative (G + C) content in DNA. Note that T increases if ionic strength is raised at constant pH (pH 7) 0.01 M phos-phate+0.001 MEDTA versus 0.15 M NaCl/0.015 MNa citrate. In 0.15 M NaCl/0.015 MNa citrate, duplex DNA consisting of 100% A T pairs melts at less than 70 C, whereas DNA of 100% G C has a T greater than 110 "C. (From Marmur Jo and Doty, R, 1962. Journal of Molecular Biology 5 120.)... 

Not only the melting temperature of DNA but also its density in solution is dependent on relative G C content. G C-rich DNA has a significantly higher density than A T-rich DNA. Furthermore, a linear relationship exists between the buoyant densities of DNA from different sources and their G C content... 

Measurement of the melting temperature (Tm) and the circular dichroism (CD) spectrum of AQ-DNA(l) shows that it is a duplex at room temperature... 

Figure 13.11 Melting temperature for DNA. At this temperature the absorbance increases because the two strands of DNA come apart.

A knowledge of melting temperature or Tm is important for designing the optimum temperature for hybridization of sample DNA with its complementary... 

List of Abbreviations PCR, polymerase chain reaction RT-PCR, reverse transcription polymerase chain reaction DNA, deoxyribonucleic acid RNA, ribonucleic acid RNase, ribonuclease mRNA, messenger RNA GABAa, y-aminobutyric acid type A cRNA, copy RNA dNTPs, deoxy nucleoside triphosphates MMLV, Mouse Moloney murine leukemia vims RT, reverse transcriptase bp, base pair Tm, melting temperature DEPC, diethylpyrocarbonate OD, optical density mL, milliliter SA-PMPs, streptavidin paramagnetic particles dT, deoxy thymidine DTT, dithiothreitol DNase, deoxyribonuclease RNasin, ribonuclease inhibitor UV, ultraviolet TBE, Tris-borate, 1 mM EDTA EDTA, ethylenediaminetetraacetic acid Buffer RET, guanidium thiocyanate lysis buffer PBS, phosphate buffered saline NT2, Ntera 2 neural progenitor cells... 

The thermodynamic parameters for the dissociation of double-stranded DNA into single strands can be obtained from a determination of the melting temperature I m as a function of the total concentration of strands Cj. The melting... 

The hybridization phase entails thermal denaturation of double-stranded DNA and incubation of the probe with the denatured DNA at a temperature 25°C below the melt temperature. Unless one is interested in partial homology, lower temperatures should be avoided. However, addition of formamide promotes the hybridization, thereby permitting the use of a lower temperature, if it should be required, to prevent structural modification. 

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