Buddy..... Is the Test tube labelled, if so just identify then based on label :-) :-) :-p Lol .

@ Mr. Raghav Oberoi: Sir, you have stated "RNA is resistant to alkaline hydrolysis whereas DNA is not". But, The fact is the 2′-hydroxyl group makes RNA susceptible to alkaline hydrolysis in solutions of pH greater than 9 or so. Conversely, the bonds between the sugar and the purine bases of DNA are more easily broken in low pH conditions than are those of RNA. So, I suspect and suggest to recheck your statement.

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@ all: I go with Clare evans, its not possible to differentiate DNA from RNA just on naked observation; the simplest method is to go with UV spec - Measuring the intensity of absorbance of the DNA solution at wavelengths 260 nm and 280 nm. Pure sample of DNA has the 260/280 ratio at 1.8. DNA contaminated with protein will have a 260/280 ratio lower than 1.8.

A sample containing only RNA following an extraction method is judged as being uncontaminated if the ratio is 1 :2 : 1, and for DNA is 1 : 1.8 : 1 (it reflects OD-230 : 260 : 280 ratio). If there is significant deviation from the ratio, then it is evident that contaminants are present and that further purification of the sample is necessary.

Further, when analyzing ratios and concentrations of DNA or RNA spectrophotometrically it is also necessary not only to derive readings at 280,260, and 230 nm but also to scan throughout the range 200-320 nm. Trace amounts of reagents used in the extraction process can influence adversely and provide misleading data that may affect any subsequent manipulation. At-least these many known problems we have while using the instrument........

@ me : IS IT REALLY POSSIBLE TO IDENTIFY DNA AND RNA BY JUST NAKED OBSERVATION whose wavelength limitation is 400 to 700. IT IS POSSIBLE if we can genetically remodel cone cells of the human eye that are sensitive to 3 wavelength ranges 419 nm (blue), 531 (green), 558 (red/yellow) at present to detect wavelength 230, 260, and 280 and regenerate cornea in such a way that it don't absorb wavelengths shorter than 315 nm. but what about the retinal damage ??????? cis-retinal can be converted into trans-retinal by any photon in 6 pico sec....... possible I will do it in my future birth if am a biochemist again.

hmmm... Good Question but i dont know the answer... Would u like to tell us??? i think the answer will be on the basis of solubilties or colour...... M i Right???

Well, i hope you can identify the protein by looking for foam/bubbles when the tube is shaken. The other two I dont know how to check without any aide. If Mr. Raghav, knows he can tell us.

well... as per my knowledge proteins shows turbidity n foams on shaking...i dont know about other two....

the other two can be identified in this way: as we know that DNA has deoxy sugar, i.e one oxygen is missing as compared to RNA having ribose sugar, so this RNA is ressistant to alkaline hydrolyiss whereas DNA is not.

Yeah how can you tell whether hydrolysis has taken place or not?

1st ly by using the hydrolytic mechanism you are surely using a chemical analysis to say anything about the composition of the tube? but your question says using of no technique( which also include chemical techniques by the way).

2ndly I dont think there is a real significance of this question apart from being a mere quiz question.

an interesting question. but the answer lets me down~

UV spectrophotometry is the answer, have a look at this nice summary of what you see for RNA, DNA and protein. http://biotech.matcmadison.edu/resources/methods/labManual/unit_4/exercise_15.htm

opps sorry... that involves an instrument. Must. read. things. carefully :)

aha

Mr. Raghav If you shake the test tube vigorously proteins will give froth, Where in case of DNA solution you are suppose to view swirling motion of DNA but in case of RNA you can't able to see any froth or swirl like things......

Protein form froth and viscous

DNA floats (cooling)

RNA sediments/turbid (cooling)

Nice to see

But he is not expressing any solution in his question itself so why can't we say by seeing the crystal nature of samples

Mr.Mhan just now i have cheked it, DNA is giving some what whitish threds if we see against light background and Where in RNA it is clear transperent

Mr.Mohan just now i have checked, in water DNA is appearing as whitish against light background where in case of RNA clear transperant..

Buddy..... Is the Test tube labelled, if so just identify then based on label :-) :-) :-p Lol .

@ Mr. Raghav Oberoi: Sir, you have stated "RNA is resistant to alkaline hydrolysis whereas DNA is not". But, The fact is the 2′-hydroxyl group makes RNA susceptible to alkaline hydrolysis in solutions of pH greater than 9 or so. Conversely, the bonds between the sugar and the purine bases of DNA are more easily broken in low pH conditions than are those of RNA. So, I suspect and suggest to recheck your statement.

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@ all: I go with Clare evans, its not possible to differentiate DNA from RNA just on naked observation; the simplest method is to go with UV spec - Measuring the intensity of absorbance of the DNA solution at wavelengths 260 nm and 280 nm. Pure sample of DNA has the 260/280 ratio at 1.8. DNA contaminated with protein will have a 260/280 ratio lower than 1.8.

A sample containing only RNA following an extraction method is judged as being uncontaminated if the ratio is 1 :2 : 1, and for DNA is 1 : 1.8 : 1 (it reflects OD-230 : 260 : 280 ratio). If there is significant deviation from the ratio, then it is evident that contaminants are present and that further purification of the sample is necessary.

Further, when analyzing ratios and concentrations of DNA or RNA spectrophotometrically it is also necessary not only to derive readings at 280,260, and 230 nm but also to scan throughout the range 200-320 nm. Trace amounts of reagents used in the extraction process can influence adversely and provide misleading data that may affect any subsequent manipulation. At-least these many known problems we have while using the instrument........

@ me : IS IT REALLY POSSIBLE TO IDENTIFY DNA AND RNA BY JUST NAKED OBSERVATION whose wavelength limitation is 400 to 700. IT IS POSSIBLE if we can genetically remodel cone cells of the human eye that are sensitive to 3 wavelength ranges 419 nm (blue), 531 (green), 558 (red/yellow) at present to detect wavelength 230, 260, and 280 and regenerate cornea in such a way that it don't absorb wavelengths shorter than 315 nm. but what about the retinal damage ??????? cis-retinal can be converted into trans-retinal by any photon in 6 pico sec....... possible I will do it in my future birth if am a biochemist again.

By DPA method you can identify DNA solution, With Orcinol method you can identify RNA solution and Blue/Purple coloration upon addition of Lowry's reagent+phenol folin you can identify a protein solution

proteins are insoluble in water whereas nucleic acids are soluble.

tube containing protein solution will form froth if you shake it.