CHAPTER 9 



Color Reactions of Nucleic Acid Components 



ZACHARIAS DISCHE 



Page 

 I. Color Reactions of Nucleic Acids and their Constituents Based on Reactions 

 of Their Sugars 286 



1. Color Reactions of Deoxyribonucleic Acid and Its Nucleotides .... 286 



a. Reaction with Diphenylamine 287 



b. Reactions of 2-Deoxyribose, DNA and Its Nucleotides with Cj-steine 

 and Sulfuric Acid 290 



(1) Cysteine Reaction of 2-Deoxyribose and DNA with 75 Vol. % 

 H2SO4 .' 291 



(2) Reaction of DNA with Cysteine and Concentrated H2SO4. ... 294 



c. Reaction of DNA with Tryptophan and Perchloric Acid 296 



d. Reaction of DNA and 2-Deoxyribose with Indole and HCl 297 



e. Reaction with Carbazole and Sulfuric Acid 298 



f. Reaction of DNA with Schiff' s Reagent 299 



g. Evaluation of Various Methods of Quantitative Determination of 



DNA and Its Constituents 299 



2. Reaction of Ribonucleic Acids 300 



a. Orcinol Reaction • 300 



b. Phloroglucinol Reaction of Euler and Hahn 302 



c. Reaction of Pentose with Cysteine and H2SO4 302 



II. Determination of Purine and Pyrimidine Bases of Nucleic Acids by Charac- 

 teristic Color Reactions 303 



1. Determination of Adenine 304 



2. Determination of Thymine 304 



3. Determination of Cytosine and Uracil 305 



The determination of nucleic acids can be based on the determination of 

 one of their three main components, namely phosphoric acid, the sugar, or 

 the nitrogenous bases. As regards the determination of phosphoric acid, 

 this procedure utilizes the differences in alkali lability of the two types of 

 nucleic acid and differences in their solubility in acids. [Of. Leslie, Chapter 

 16.] It is clear that these methods of determination cannot be regarded as 

 specific, and, while it was found that in certain tissues like liver,^ the meth- 

 ods give satisfactory results as far as agreement with other methods is 

 concerned, it was reported more recently^ that in some tissues, like certain 



' W. C. Schneider, J. Biol. Chem. 161, 293 (1945); 164, 797 (1946). 

 ' L. Drasher, Science 118, 181 (1953). 



285 



