Bromine Analysis in 5-Bromouracil-Labeled DNA by X-ray Fluorescence

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Science  27 Dec 1963:
Vol. 142, Issue 3600, pp. 1670-1673
DOI: 10.1126/science.142.3600.1670


The degree of replacement of thymine by 5-bromouracil in the deoxyribonucleic acid (DNA) of the thymine-deficient bacterium Escherichia coli B 15 T- has been determined by a nondispersive x-ray fluorescence method. A measure of the fraction by weight of bromine in the purified DNA is required for determining the degree of thymine replacement. This fraction is experimentally determined on 35-µg samples of DNA by x-ray spectroanalysis.