DNA or RNA will brake in nucleotides only if you to use chemicals (such as NaOH 5M or hydrogen peroxide) or enzymes (Desoxyribonucleases and Ribonucleases) to do this because it is necessary break the phosphodiester bonds, a sigma bond. The temperarute will promote only the hydrogen bonds broken denaturating the double strands (in DNA) or secundary structures (in RNA).

94-98' c as in the denaturation step in PCR in which the heat is arised to 94-98 C causing melting of DNA by destruction of the hydrogen bonds resulting in the formation of single stranded DNA

@Eslam: are you sure about that? in the PCR denaturation you aim for separating the double strands in order to make the primer binding possible. but this binding is, as you stated, due to hydrogen bonds which are much less stable than the phosphate-deoxiribose bindings between the nucleotides.

A common formula for the calculation of the melting temperature of nucleotides is the Wallace equation, that is tied to a specific saline concentration (0.9M NaCl).

Wallace equation for a 50% denaturation(!) of an oligonucleotide depending on it's ACGT content:

Td = 2°C(A+T) + 4°C(G+C)

I do not think dissociation into single nucleotides is the major pathway for thermal decomposition of nucleic acids. Other processes will occur to degrade the DNA before the phosphate linkage is broken.

This question is quite different from asking what the temperature of melting is, which is well addressed by the replies above.

In our lab we treat DNA in 6% perchloric acid sulution for 15-20 minutes at 100 C to achieve sure denaturation of DNA.

I failed to find the article describing the process in English, sorry. I'd refer to the article by Spirin published in 1960ies.

Denaturation in aqueous solution is at least reversible, and I don't think the single strands dissociate completely at temperatures below 100 C.

Thanks to Akhilesh,Eslam, Sebastian, Roman, Mr Michael Norton. @Roman: is that treatment break the phosphate bond because i want to try that , @ Michael Norton;it may not be possible in in vivo, because of degrading enzyme but can we do it in vitro without using enzyme?..............and i want to break the phosphate bond(into single nucleotide from single or double strand DNA or RNA) not hydragen bond...is it posssible at any temperature or any chemical method?...

Dear all,

I want someone make me understanding "Through PCR, dose DNA be separated or just denaturated?"

@Eslam, Through PCR we are just breaking the double strand into single strand in order to allow binding of primer to single strand DNA to get multiple copies using polymerase....denaturation is nothing but a lose of it's native state. it can be breaking of hydrogen bond(from double strands to single strand) or phosphate bond(from single or double strands to single nucleotides)....Because DNA can DENATURE(into single strands) at extreme temp, pH, acidic or basic condition and RE NATURE(binding of single strands into double strands due to it's complementarity) at it's native condition like optimum temp,pH,acidic and basic...

@Dhanasekaran, do you mean that upon extrem temp use ,DNA will be separated into single stands but it will renature at rapid extent through which you can not do your need work so you are obligated to use chemicals which acheive complete separtation for a prolonged period?

Sorry for disturbance and thanks inadvance

With alkali treatment it will get denatured ... Above 85 c it will degrade but it will get renature soon so control that

renaturation...

DNA or RNA will brake in nucleotides only if you to use chemicals (such as NaOH 5M or hydrogen peroxide) or enzymes (Desoxyribonucleases and Ribonucleases) to do this because it is necessary break the phosphodiester bonds, a sigma bond. The temperarute will promote only the hydrogen bonds broken denaturating the double strands (in DNA) or secundary structures (in RNA).

Thanks to Jaykishan and Juliano.......@Eslam: i don't want to separate into single strands, i want to break into single nucleotides, because we cannot achieve renaturation if we broken the phosphate bond.

Thanks all......Really apperciate ur knowledge

Please fogive my ignorance

@Eslam: Don't take like that all..Because we are here to ask and discuss the thing which we don't know, if i don't know something, definitely somebody know the answer, so i can make myself clear by asking. also we'll get different answer from different people, that make us to strong in that thing....Even i don't know everything...i just know before u know, that is the difference.....So don't failure to ask...

@Dhanasekaran: I totally agree with you. What I meant that I am still an undergraduate student and I will follow your advise and keep asking.........nice to meet you Dhanasekaran

what is the process of DNA degradation and causes .?