A study of the conditions and mechanism of the diphenylamine reaction for the colorimetric estimation of deoxyribonucleic acid
Reads0
Chats0
TLDR
The present study arose from the observation that a more intense colour was sometimes produced if, instead of being heated at 1000 for 10 min., the reaction mixture was allowed to stand overnight at room temperature.Abstract:
Of the colour reactions available for the determination and identification of deoxyribonucleic acid (DNA), the reaction with diphenylamine in a mixture of acetic and sulphuric acids at 1000 (Dische, 1930) has been perhaps the most widely used. The present study arose from the observation that a more intense colour was sometimes produced if, instead of being heated at 1000 for 10 min., the reaction mixture was allowed to stand overnight at room temperature. As a result of this observation the procedure has been modified, principally by adding acetaldehyde to the reagents and by allowing the solution to stand for about 17 hr. at 30° instead of heating it at 1000. The modified method is 3-5 times as sensitive as Dische's original procedure, and several substances which interfere in the original method do not do so in the modified procedure. Some observations on the mechanism of the reaction have been made; in particular it was discovered that there is a liberation of inorganic orthophosphate from DNA during the early stages of the reaction. This finding has a bearing on the structure of DNA. The modified method has already been used in an investigation of nucleic acid metabolism during bacteriophage multiplication (Burton, 1955).read more
Citations
More filters
Journal ArticleDOI
Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction
TL;DR: A new method of total RNA isolation by a single extraction with an acid guanidinium thiocyanate-phenol-chloroform mixture is described, providing a pure preparation of undegraded RNA in high yield and can be completed within 4 h.
Journal ArticleDOI
Isolation of biologically active ribonucleic acid from sources enriched in ribonuclease.
TL;DR: In this article, the rat pancreas RNA was used as a source for the purification of alpha-amylase messenger ribonucleic acid (RBA) using 2-mercaptoethanol.
Journal ArticleDOI
A rapid and simple method for measuring thymocyte apoptosis by propidium iodide staining and flow cytometry
TL;DR: A flow cytometric method for measuring the percentage of apoptotic nuclei after propidium iodide staining in hypotonic buffer is developed and shown an excellent correlation with the results obtained with both electrophoretic and colorimetric methods.
Journal ArticleDOI
Glucocorticoid-induced thymocyte apoptosis is associated with endogenous endonuclease activation
TL;DR: It is shown here that this morphological change is closely associated with excision of nucleosome chains from nuclear chromatin, apparently through activation of an intracellular, but non-lysosomal, endonuclease.
Journal ArticleDOI
Levels of glutathione, glutathione reductase and glutathione S-transferase activities in rat lung and liver.
TL;DR: The activities of some glutathione-metabolizing enzymes were observed to be 5-to 60-fold lower in lung tissue than in the liver, and that phenobarbital nor methylcholanthrene had a significant effect on the levels of reduced glutATHione in lung and liver.
References
More filters
Journal ArticleDOI
An improved method for the colorimetric determination of phosphate.
I. Berenblum,E. Chain +1 more
Journal ArticleDOI
A sensitive method for the determination of deoxyribonucleic acid in tissues and microorganisms.
Junius M. Webb,Hilton B. Levy +1 more
Journal ArticleDOI