Why is diphenylamine used for DNA estimation?
The deoxyribose in DNA in the presence of acid forms β-hydroxylevulinaldehyde which reacts with diphenylamine to give a blue colour with a sharp absorption maximum at 595nm. In DNA, only the deoxyribose of the purine nucleotides react, so that the value obtained represents half of the total deoxyribose present.
What diphenylamine reagent is used for?
Diphenylamine is an aromatic amine containing two phenyl substituents. It has been used as a fungicide for the treatment of superficial scald in apples and pears, but is no longer approved for this purpose within the European Union.
What is the use of DPA method?
In this way, diphenylamine can be used for the simultaneous determination of the concentrations of DNA and RNA in mixtures. As is the case for the reaction of DNA with diphenylamine, it was found that the reaction of RNA is not altered by the presence of protein and that it involves primarily the purine nucleotides.
Why is diphenylamine used as an indicator?
Diphenylamne is used as an indicator because it shows a very clear color change from green to violet when end point of the titration is reached. Usually phosphoric acid is added to the Fe2+ solution (ferrous ammonium sulfate) if that is the reductant that is being titrated, so that the Fe3+ product may be stabilized.
Is diphenylamine toxic?
On the basis of mammalian toxicity data Diphenylamine is classified as toxic. Therefore, an assessment of secondary poisoning is carried out.
What is the color produced upon addition of diphenylamine reagent?
The blue color that has been obtained by the action of nitrosamines, nitrates, nitrites, and aliphatic nitro- compounds on diphenylamine in sulfuric acid has been regarded [1]1 as a specific test for these sub- stances in the absence of various oxidizing agents that also produce a blue color.
What is diphenylamine method?
The diphenylamine method is a colorimetric reaction based on the specific reaction of diphenylamine with deoxyribose residues resulting in a complex that absorb at 600 nm (Burton 1956).
What is the chemical reaction involved in diphenylamine test?
DNA can be identified chemically with the Dische diphenylamine test. Acidic conditions convert deoxyribose to a molecule that binds with diphenylamine to form a blue complex. The intensity of the blue color is proportional to the concentration of DNA. The amount of blue corresponds to the amount of DNA in solution.
How is diphenylamine an internal indicator?
Diphenylamne is used as an indicator because it shows a very clear color change from green to violet when end point of the titration is reached. Usually phosphoric acid is added to the Fe2+ solution if that is the reductant that is being titrated, so that the Fe3+ product may be stabilized.
Which type of indicator is diphenylamine?
Redox indicator Many diphenylamine derivatives are used as redox indicators that are particularly useful in alkaline redox titrations.
How is colorimetric reaction of diphenylamine and DNA produced?
A colored solution, absorbing maximally at 600 nm, is produced by reacting acid-hydrolyzed DNA with diphenylamine in the presence of sulfuric acid, acetic acid, and acetaldehyde at 25 to 35°C for 15 h. The chemical nature of the chromophore is unknown, although at least two colored compounds are thought to be formed (1).
How is diphenylamine used in two wavelength spectrum analysis?
When the two-wavelength method of spectrum analysis was applied to such spectra, good agreement was found between actual and calculated values of nucleic acid concentrations. In this way, diphenylamine can be used for the simultaneous determination of the concentrations of DNA and RNA in mixtures.
How long does it take for RNA to react with diphenylamine?
RNA does not react appreciably after 10 or 30 minutes, but after hydrolysis for 1 hour or more significant absorbances are recorded, showing that RNA reacts with diphenylamine to produce a colored product. It was possible to differentiate visually the DNA reaction product (blue) and the RNA reaction product (blue-green).
Is the diphenylamine reaction specific to 2-deoxyribose?
Overend, Shafizadeh, and Stacey, (4) found that the diphenylamine reaction is not specific for 2-deoxyribose but rather is a general reaction for 2-deoxypentoses. They also demonstrated that the reaction depends upon the hydrolytic conversion of 2-deoxypentoses to 5-hydroxylevulic aldehyde.