A Proposed General Procedure for Isolating End-Groups of Nucleic Acids^*

Dnases and Their Use in the Studies of Primary Structure of Nucleic Acids

“…Holley et al (94) used phosphomonoesterase to dephosphorylate an oligomer and venom phosphodiesterase to produce a series of oligomers differing by a single unit. The mixture of newly formed oligomers was chromatographed on Tomlinson and Tener's column (230). Each of the oligomers was then hydrolyzed by alkali and only a nucleoside was identified.…”

Composition of the 3′‐Phosphate Penultimate Nucleotides Released from Calf‐Thymus DNA by Spleen Acid DNAase

“…The products of pancreatic DNAase digestion were resolved on a DEAE-cellulose-urea column (see Results and Fig. 5 ) and treated as follows : (a) dinucleoside monophosphates (peak 1 of the chromatogram) were desalted and analyzed as described by Ehrlich et al [2] for their hydrolysate 11; (b) the identification of components present in peaks 2 and 3 were done on the basis of their elution position and their relative amounts in the digest ; (c) trinucleotides and nucleoside diphosphates (peak 4 of the chromatogram) were diluted 10 times and desalted by readsorption on DEAE-cellulose, elution with 1.0 M ammonium acetate [7] and freeze-drying. After dephosphorylation, nucleosides were separated from trinucleoside diphosphates on a DEAE-cellulose column (0.4 x 4 cm) and analyzed on a BioGel P-2 column [8].…”

Instabilité en Milieu Alcalin des Oligodésoxynucléotides Radio-induits

“…Les prot6ines sont dosees par le procede de Lowry, Rosenbrough, Farr et Randall (1951). La teneur en ARN est dterminee par la m6thode de Vokin et Cohn (1957). Les preparations d'ADN utilis~es contiennent moins del pour cent d'ARN ou de proteines.…”

“…Tous les gradients lin6aires de NaCl utilises sont forms dans l'ure 7 M tamponn6e pH 7,6 par 0,02 M tris (Tomlinson et Tener 1963 a).…”

“…La precipitation par l'acide perchlorique d'&hantillons d'ADN irradi a permis de vrifier ces provisions. Par la suite, de courts oligonucleotides radio-induits sont fractionn6s, sur la base de leur charge ngative nette (Tomlinson et Tener 1963 a), sur colonne de DEAE-Sephadex (Rushizky, Bartos et Sober 1964) en presence M. Simon d'ur6e 7 M. Un second fractionnement des produits de degradation alcaline, pr&cde d'une dphosphorylation enzymatique (Tomlinson et Tener 1963 b), ou d'une hydrolyse acide partielle des phosphates cycliques terminaux permet leur analyse. Une interpretation des mcanismes chimiques des ruptures induites par les radiations ionisantes est donnee.…”