scholarly journals Determination of the base composition of deoxyribonucleic acid by measurement of the adenine/guanine ratio

1967 ◽  
Vol 105 (2) ◽  
pp. 673-677 ◽  
Author(s):  
J. T. O. Kirk
Keyword(s):  
Standard Deviation ◽  
Hydrochloric Acid ◽  
Base Composition ◽  
Deoxyribonucleic Acid ◽  
Exchange Chromatography ◽  
Molar Ratio ◽  
Calf Thymus ◽  
Guanine And Adenine ◽  
Adenine Thymine

A method is described for determination of the base composition (as guanine+cytosine or adenine+thymine content) of DNA by accurate measurement of the adenine/guanine ratio. The DNA is hydrolysed with 0·03n-hydrochloric acid for 40min. to release the purines. The hydrolysate is subjected to ion-exchange chromatography on Zeo-Karb 225. Apurinic acids are eluted with 0·03n-hydrochloric acid and then guanine and adenine are eluted separately with 2n-hydrochloric acid. Guanine and adenine are each collected as a single fraction, and the amount of base in each case is determined by measuring the volume and the extinction at suitable wavelengths. For use in the calculations, millimolar extinction coefficients in 2n-hydrochloric acid of 12·09 for adenine at 262mμ, and 10·77 for guanine at 248mμ, were determined with authentic samples of bases. The method gives extremely reproducible results: from 12 determinations with calf thymus DNA the adenine/guanine molar ratio had a standard deviation of 0·011; this corresponds to a standard deviation in guanine+cytosine content of 0·2% guanine+cytosine.

The Determination of the DNA Base Composition in 19 Species of Adriatic Sponges with High-Pressure Liquid Cation-Exchange Chromatography

1976 ◽  
Vol 31 (9-10) ◽  
pp. 554-557 ◽  
Author(s):  
Hans-Joachim Breter ◽  
Ferdinand Hundt ◽  
Rudolf K. Zahn
Keyword(s):  
High Pressure ◽  
Cation Exchange ◽  
Base Composition ◽  
Exchange Chromatography ◽  
Cation Exchange Chromatography ◽  
Dna Base Composition ◽  
Dna Base ◽  
Semiquantitative Method ◽  
Adenine Thymine

Abstract The (adenine + thymine)/(guanine + cytosine) base ratios of 19 species of adriatic sponges have been determined by high-pressure liquid cation-exchange chromatography. The base ratios vary from 1.49 (Mycale massa) to 0.63 (Hippospongia communis) according to an (A+T) content of 59.7 and 38.6 mol%, respectively. The DNAs of sponges of the order Keratosa showed marked differences in their (A +T) contents (39.5 to 58.8 mol%) whereas those of Tetractinellida and Halichondrina were nearly identical (39.3 to 40.8 and 49.5 to 49.8 mol%, respectively). The 5-methylcytosine (5MC) content was determined in 8 sponge DNAs by a semiquantitative method. The values differed from 0.8 to 2.2 mol% of 5MC.

HYDROLYSIS OF CALF THYMUS DEOXYRIBONUCLEATE BY PANCREATIC DEOXYRIBONUCLEASE: I. A STUDY OF THE OLIGONUCLEOTIDES LIBERATED IN THE PRESENCE OF MAGNESIUM OR MANGANESE IONS

1963 ◽  
Vol 41 (1) ◽  
pp. 469-480 ◽  
Author(s):  
R. O. Hurst ◽  
G. C. Becking
Keyword(s):  
Metal Ion ◽  
Deoxyribonucleic Acid ◽  
Exchange Chromatography ◽  
Magnesium Ions ◽  
Manganese Ions ◽  
Terminal Position ◽  
Deoxyribonuclease I ◽  
Calf Thymus ◽  
Hydrolysis Of

The oligonucleotides obtained from deoxyribonucleic acid by the action of pancreatic deoxyribonuclease in the presence of magnesium ions or manganous ions have been analyzed by ion exchange chromatography and by determination of the relative amounts of purine and pyrimidine deoxynucleotides occupying the 5′-terminal position. Evidence of a difference in the specificity of action of the enzyme that is dependent upon the nature of the metal ion activator employed has been adduced.

HYDROLYSIS OF CALF THYMUS DEOXYRIBONUCLEATE BY PANCREATIC DEOXYRIBONUCLEASE: I. A STUDY OF THE OLIGONUCLEOTIDES LIBERATED IN THE PRESENCE OF MAGNESIUM OR MANGANESE IONS

1963 ◽  
Vol 41 (2) ◽  
pp. 469-480 ◽  
Author(s):  
R. O. Hurst ◽  
G. C. Becking
Keyword(s):  
Metal Ion ◽  
Deoxyribonucleic Acid ◽  
Exchange Chromatography ◽  
Magnesium Ions ◽  
Manganese Ions ◽  
Terminal Position ◽  
Deoxyribonuclease I ◽  
Calf Thymus ◽  
Hydrolysis Of

The oligonucleotides obtained from deoxyribonucleic acid by the action of pancreatic deoxyribonuclease in the presence of magnesium ions or manganous ions have been analyzed by ion exchange chromatography and by determination of the relative amounts of purine and pyrimidine deoxynucleotides occupying the 5′-terminal position. Evidence of a difference in the specificity of action of the enzyme that is dependent upon the nature of the metal ion activator employed has been adduced.

Determination of the DNA binding properties of a novel PARP inhibitor MK-4827 with calf-thymus DNA by molecular simulations and detailed spectroscopic investigations

2019 ◽  
Vol 43 (17) ◽  
pp. 6702-6711 ◽  
Author(s):  
Hongqin Yang ◽  
Qingle Zeng ◽  
Ze He ◽  
Di Wu ◽  
Hui Li
Keyword(s):  
Dna Binding ◽  
Deoxyribonucleic Acid ◽  
Parp Inhibitor ◽  
Molecular Simulations ◽  
Binding Interaction ◽  
Binding Properties ◽  
Calf Thymus ◽  
Polymerase Inhibitor ◽  
Dna Binding Properties

The binding interaction of niraparib (MK-4827), a poly(ADP-ribose) polymerase inhibitor, with calf thymus deoxyribonucleic acid (ctDNA) has been explored by various theoretical and experimental techniques.

scholarly journals Determination of Polydextrose as Dietary Fiber in Foods

2000 ◽  
Vol 83 (4) ◽  
pp. 1006-1012 ◽  
Author(s):  
Stuart A S Craig ◽  
James F Holden ◽  
Maha Y Khaled
Keyword(s):  
Standard Deviation ◽  
Dietary Fiber ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Physiological Effects ◽  
Total Dietary Fiber ◽  
Internal Validation ◽  
Relative Standard ◽  
Centrifugal Ultrafiltration

Abstract Polydextrose (Litesse®) provides physiological effects consistent with dietary fiber. However, AOAC methods for measuring total dietary fiber (TDF) in foods include an ethanol precipitation step in which polydextrose and similar carbohydrates are discarded and therefore not quantitated. This study describes a method developed to quantitate polydextrose in foods. The new method includes water extraction, centrifugal ultrafiltration, multienzyme hydrolysis, and anion exchange chromatography with electrochemical detection. Six foods were prepared with 4 levels of polydextrose to test the ruggedness of the method. Internal validation demonstrated the ruggedness of the method with recoveries ranging from 83 to 104% with an average of 95% (n = 24) and relative standard deviation of recoveries ranging from 0.7 to 13% with an average of 3.3% (n = 24). The value is added to that obtained for dietary fiber content of foods using the AOAC methods, to determine the TDF content of the food.

scholarly journals FURTHER STUDIES OF INFECTIOUS DNA EXTRACTED FROM MYCOBACTERIOPHAGES

1966 ◽  
Vol 123 (2) ◽  
pp. 327-340 ◽  
Author(s):  
Margret I. Sellers ◽  
Tohru Tokunaga
Keyword(s):  
Mycobacterium Smegmatis ◽  
Base Composition ◽  
Thermal Denaturation ◽  
Buoyant Density ◽  
Plaque Formation ◽  
Double Stranded Dna ◽  
Calf Thymus ◽  
Phage Dna ◽  
Dna Thermal Denaturation ◽  
Adenine Thymine

Results of the previous investigation in which it was found that DNA extracted from D29 mycobacteriophage was infectious for Mycobacterium smegmatis 607, have been extended. DNA extracted from mycobacteriophage D4 and D32 produced plaques when plated on their respective hosts; D28 DNA, extracted in the same manner and tested under similar conditions, failed to show infectivity. Species barriers were not crossed by mycobacteriophage DNA; bacteria resistant to intact phage were not infected with the phage DNA. The efficiency of plating of the DNA is very much lower than that of intact phage; infection of a given host was not accomplished by DNA when titration for plaque formation by the intact phage was less than 109 PFU. The base composition of DNA extracted from the four mycobacteriophages and the three propagating hosts was very similar. The bases were paired, adenine with thymine and guanine with cytosine. A relatively higher per cent of guanine-cytosine than of adenine-thymine, was found. The buoyant density of each DNA in CsCl was linearly related to its guanine-cytosine content whereas with the exception of D28 DNA, thermal denaturation temperatures failed to show this relationship. However, the thermal transition profiles were characteristic of double stranded DNA. Additional evidence that D29 DNA forms complexes with basic proteins was obtained. Binding between calf thymus histone and between RNAase and D29 DNA readily occurs with a resultant loss in DNA infectivity. Trypsin and D29 DNA are only weakly reactive.

scholarly journals A Method for the Determination of Nicotine in Lung Tissue of Hamsters / Eine Methode zur Bestimmung des Nikotins in Hamsterlungen

1966 ◽  
Vol 3 (6) ◽  
Author(s):  
H. Elmenhorst
Keyword(s):  
Standard Deviation ◽  
Hydrochloric Acid ◽  
Lung Tissue ◽  
Coefficient Of Variation ◽  
Steam Distillation ◽  
Analytical Procedure ◽  
Limit Of Detection ◽  
Experimental Animals ◽  
Inferior Limit

AbstractA method for the determination of nicotine in lung tissue is presented. The nicotine is extracted from homogenized lung tissue by means of a mixture of hydrochloric acid and methanol. It is then spectrophotometrically determined after the disturbing accompanying substances have been eliminated by a preliminary acid steam distillation. The method's inferior limit of detection is 40 µg of nicotine contained in 3 lungs, which corresponds to 17.7 µg of nicotine per gramme of lung tissue. In the case of nicotine contents of 50 µg per analytical procedure the standard deviation of the method was found to be 1.7 µg, and the resulting coefficient of variation was calculated to be 3.4 %. The procedure is simple and therefore suitable for the study of numerous samples. The exposure of hamsters to inhaled raw cigarette smoke revealed that the nicotine content of lungs of experimental animals augments with the number of burnt cigarettes and the duration of inhalation. The reproducibility of Dontenwill's inhalation procedure was tested and proved to be satisfactory. The coefficient of variation within two series of inhalation experiments was found to be between 4.1 and 5.2 %

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