Abstract
1. Sialic acid has been found to interfere with three colorimetric reactions used for the estimation of DNA: a modified diphenylamine reaction at 100° (Dische, 1930), the nitrophenylhydrazine method (Webb & Levy, 1955) and the diphenylamine reaction at 30° (Burton, 1956). 2. Evidence is presented that sialic acid is present in hydrolysates obtained from gastric wash-out material. 3. A mathematical method for correcting for interference from sialic acid in the diphenylamine reaction at 30° is described. 4. The diphenylamine reaction has been modified to make it suitable for the estimation of DNA in the presence of sialic acid. The modifications are to increase the concentration of diphenylamine to 2% and to perform the reaction at 6–13° for 48hr. These modifications increase the sensitivity 25% above Burton's (1956) modification of the diphenylamine reaction. 5. The precipitation, extraction and recovery of DNA from gastric wash-out material have been investigated.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BURTON K. A study of the conditions and mechanism of the diphenylamine reaction for the colorimetric estimation of deoxyribonucleic acid. Biochem J. 1956 Feb;62(2):315–323. doi: 10.1042/bj0620315. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CROFT D. N. ASPIRIN AND THE EXFOLIATION OF GASTRIC EPITHELIAL CELLS. CYTOLOGICAL AND BIOCHEMICAL OBSERVATIONS. Br Med J. 1963 Oct 12;2(5362):897–901. doi: 10.1136/bmj.2.5362.892. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LEE J. B. COMPOUNDS INTERFERING IN THE DIPHENYLAMINE TEST FOR DEOXYRIBONUCLEIC ACID. Nature. 1963 Oct 19;200:264–266. doi: 10.1038/200264a0. [DOI] [PubMed] [Google Scholar]
- WEBB J. M., LEVY H. B. A sensitive method for the determination of deoxyribonucleic acid in tissues and microorganisms. J Biol Chem. 1955 Mar;213(1):107–117. [PubMed] [Google Scholar]
- WEBB J. M., LEVY H. B. New developments in the chemical determination of nucleic acids. Methods Biochem Anal. 1958;6:1–30. doi: 10.1002/9780470110225.ch1. [DOI] [PubMed] [Google Scholar]