Table of Contents
- 1 What is the use of diphenylamine test?
- 2 What is tested in diphenylamine test?
- 3 What is the chemical reaction involved between diphenylamine and DNA?
- 4 What is DPA method?
- 5 Is RNA detected by diphenylamine?
- 6 Are DNA and RNA reducing sugar?
- 7 How is diphenylamine used in the Dische test?
- 8 Is the compound diphenylamine soluble in organic solvents?
What is the use of diphenylamine test?
A presumptive test for nitrates. The reagent is a solution of diphenylamine (C6H5)2NH) in sulphuric acid. A positive result is indicated by a blue colour. It was once used in testing for gunshot residue, but is not particularly reliable.
What is the composition of diphenylamine reagent *?
The reagent is a solution of 0.5% diphenylamine in 90% sulphuric acid. To prepare the reagent, slowly add 90 mL of concentrated sulphuric acid to 10 mL of water while stirring continuously, and then add this, in successive small portions, to 0.5 g of diphylamine.
What is tested in diphenylamine test?
This is a color test for the presence of nitrates or nitrites. Use caution! This reagent contains concentrated sulfuric acid (H2SO4).
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 is the chemical reaction involved between diphenylamine and DNA?
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.
Is diphenylamine test conclusive?
The (Diphenylamine or Parrafin) test is not conclusive as to the presence of gunpowder because fertilizers, cosmetics, cigarettes, urine, and other nitrogenous compounds with nitrites and nitrates will give a positive reaction. This (Diphenylamine or Parrafin) test has proved extremely unreliable in use.
What is DPA 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).
Why purple ring is formed in Molisch test?
Molisch’s Test: It is based on the dehydration of the carbohydrate by Sulphuric acid to produce an aldehyde, which condenses with two molecules of α-naphthol, resulting in appearance of a purple ring at the interface.
Is RNA detected by diphenylamine?
RNA has been demonstrated to react with diphenylamine when acid hydrolysis is performed for 1 hour or more at 100°C. This reaction can be used for quantitative analysis of RNA, since there is a linear relationship between RNA concentration and absorbance.
Why does DNA absorb at 260?
Nucleic acids strongly absorb UV light with wavelengths of 260 nm due to the resonance structure of the purine and pyrimidine bases [7]. The absorbance is converted into ng/μL of double stranded DNA (dsDNA) using the established conversion factor of 50 ng/μL for 1 optical density unit at 260 nm [9].
Are DNA and RNA reducing sugar?
Carbohydrates – Ribose. Ribose and its related compound, deoxyribose, are the building blocks of the backbone chains in nucleic acids, better known as DNA and RNA. Ribose and deoxyribose are classified as monosaccharides, aldoses, pentoses, and are reducing sugars.
How is diphenylamine used in the industrial world?
DPA is a colorless-to-brown crystalline solid that finds a number of industrial/commercial applications, for example, in the manufacture of dyes and the protection of apples during storage. Diphenylamine is present in waste water from industrial processes.
How is diphenylamine used in the Dische test?
The Dische’s Test will detect the deoxyribose of DNA and will not interact with the ribose in RNA. The amount of blue corresponds to the amount of DNA in solution. The diphenylamine compound of the Dische’s test interacts with the deoxyribose of DNA to yield a blue coloration.
How does diphenylamine affect the color of DNA?
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 Dische’s Test will detect the deoxyribose of DNA and will not interact with the ribose in . The amount of blue corresponds to the amount of DNA in solution.
Is the compound diphenylamine soluble in organic solvents?
The compound is a derivative of aniline, consisting of an amine bound to two phenyl groups. The compound is a colorless solid, but commercial samples are often yellow due to oxidized impurities. Diphenylamine dissolves well in many common organic solvents, and is moderately soluble in water. It is used mainly for its antioxidant properties.