Deoxyribonucleic acid melting temperature

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... 

Figure 10.24 Relationship between the G + C content of DNA and its melting temperature. Experiments were done at two different ionic strengths. Numbers indicate DNA sources 1 is an A-T copolymer, whereas 41 is a G-C copolymer 2 is Clostridia perfringens, and 40 is Streptococcus viridochromogenes. (Reproduced by permission from Marmur J, Doty R Determination of the base composition of deoxyribonucleic acid from thermal denatura-tion temperature. J Mol Biol 5 109-118, 1962.)...

Freund A.M. and Bernardi G. (1963). Viscosity of deoxyribonucleic acid solutions in the sub-melting temperature range. Nature (London), 200 1318-1319. 

The mutual repulsion between substituents may cause some displacement. As a result, the plane of symmetry is bent in the form of a helix. This occurs also in biopolymers (double-helix of deoxyribonucleic acid (DNA)). Different stereoisomers have different mechanical and thermal properties. For example, atactic polystyrene is an amorphous polymer whereas syndiotactic polystyrene is a crystalline substance. The chemical design of macromolecules determines their properties as extent of crystallization, melting point, softening (glass transition temperature), and chain flexibility which in turn strongly influence mechanical properties of the materials. 

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