DEGRADATION OF DNA BY HYDRAZINE - A CRITICAL STUDY OF SUITABILITY OF REACTION FOR QUANTITATIVE DETERMINATION OF PURINE NUCLEOTIDE-SEQUENCES

A quantitative study has been made of the reaction of hydrazine under various conditions with deoxyribonucleotides and with DNA. The properties of the apyrimidinic acid produced in the latter reaction have been investigated. 1. 1. Under no conditions was quantitative estimation of deoxyribose possible after hydrazinolysis and benzaldehyde treatment of pyrimidine deoxyribonucleotides or DNA. 2. 2. Treatment of apyrimidinic acid preparations with diphenylamine and formic acid failed in every case to release all of the phosphorus as inorganic phosphate. 3. 3. Progressive degradation of adenine was observed during hydrazinolysis at 60°, but little or no loss occurred at 30°. 4. 4. Apyrimidinic acid prepared under mild conditions contained unidentified pyrimidine degradation products which could be liberated by treatment with alkali. 5. 5. Under all conditions tested, the cytosine residues in DNA reacted with hydrazine to yield 3-ureidopyrazole in approx. 50% yield, in addition to the expected 3-aminopyrazole. © 1969.