Diphenylamines reaction

Burton K (1956) A study of the conditions and mechanism of the diphenylamine reaction for the colorimetric estimation of deoxyribonucleic acid. Biochem. 62 315-323. 

The test depends on the 2-desoxyribose component of the nucleic acid and in experiments directed towards the synthesis of this sugar and its derivatives, the diphenylamine reaction has been used to obtain indications of the formation of the required product. Originally it was claimed that the test was specific for 2-desoxyribose but more recent investigations by Stacey and his coworkers48 have shown that the test is given by 2-desoxypentoses generally. Moreover, these workers have elucidated in part the mechanism of the test.48 These studies will be discussed more fully subsequently. 

Gurin and Hood88 have demonstrated that addition of a solution of carbazole to an ice-cold mixture of sulfuric acid and 2-desoxyribose results in the formation of an intense yellow color. This test, however, is not as suitable as the diphenylamine reaction for the detection and estimation of 2-desoxyribose. It is markedly unspecific since sulfuric... 

Slater, T. F., and Lovell, D., Increased serum diphenylamine reaction in patients with leukemia. Experientia 17, 272-274 (1961). 

Fig. 22. Optical density of the diphenylamine reaction in the gastric juice in various gastric diseases and in normal controls.

This unsatisfactory state of affairs changed in 1984 with a proposal [21] that these abnormal kinetics were a consequence of the inhomogeneity of the matrix. In the experiments that were carried out [21], the methyl radicals were produced in a methanol glass from methyl halides by photo-induced electron capture using traces of diphenylamine, reaction (28.17). It was suggested [21] that the radicals... 

DNA was determined by the diphenylamine reaction (10). Two 45 minute extractions at 70°C with. 5N HCIO were used to release DNA from the sample pellets. Interference from guanidine was accounted for by making each sample. 4M guanidine. 

Diphenylamine reaction product with styrene and diisobutylene. Agerite Stalite Benzenamine, N-phenyl-, reaction products with styrene and 2,4,4-trimethylpentene Diphenylamine reaction product with styrene and diisobutylene EINECS 272-940-1 Reaction product of N-phenylbenzenamine, ethenylbenzene, and... 

Perhaps the main disadvantage of the diphenylamine reaction for de-soxypentose is the lack of sensitivity. In addition, interference in the test by some substances has been shown by certain investigators (17,21,23,44). Three recently proposed methods deserve serious consideration. Cohen (23) has developed a color reaction with tryptophane, while Stumpf (98) has standardized the cysteine reaction originally proposed by Dische (40). Both methods are accurate in the range of 50-500 / g. of DNA. Ceriotti (21) has developed a micromethod (2.5-15 /xg. of DNA) using the reaction of indole with DNA, followed by extraction of the yellow pigment with chloroform. 

Caldwell and Hinshelwood (17) have applied the orcinol and diphenylamine reactions to whole bacterial suspensions or their hot tridiloroacetic acid extracts and have shown that, by extrapolation of the time curves of the color reactions, the additional amount of coloration due to interfering material can be eliminated. 

Protein synthesis. Cohen has also endeavored to measure protein synthesis in the infected system by taking the difference of the total N minus DNA-N (52,54,62). This procedure is open to question on several counts. For example, proteolysis occurs as is indicated by the dip in the protein N curve of Fig. 6. Also, DNA is measured as deoxypentose by the diphenylamine reaction and a nitrogen factor has had to be assumed which takes no account of the possibility that the sugar may be accumulating in some form other than DNA. Consequently, the argument that the ratio of the rates of increment of N and P utilization (54) is similar to that of normal cells is a matter still open to question as inspection of Fig. 6 will reveal The same criticism attaches to the conclusion mentioned above that only virus or virus components are synthesized. 

ADPA Acetone-diphenylamine reaction product AgeRite Superflex ... 

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