Biomaterial Database

A simple method for measuring specific radioactivities of ribonucleoside triphosphates using RNA polymerase. 1976

R E Maxson, and R S Wu

We describe a method for the rapid, one-step determination of the specific radioactivity and pool size of ATP, UTP, CTP or GTP. Escherichia coli RNA polymerase and poly[d(A-T)] or poly[d(G-C)] are used to synthesize an alternating copolymer from a [3H]nucleoside triphosphate of unknown specific activity and a [14C]nucleoside triphosphate of known specific activity. The fact that [3H]nucleotide and [14C]nucleotide are incorporated into poly[r(A-U)] or poly[r(G-C)] in equimolar amounts, coupled with a knowledge of the [14C]nucleotide specific activity, permits calculation of the [3H]nucleotide specific activity. The requirement for direct knowledge of the [14C]nucleotide specific activity may be bypassed by an isotope dilution procedure. The pool size of a nucleoside triphosphate can be estimated either from isotope dilution data or by determining the fraction of [3H]nucleotide polymerized, dividing the number of counts 3H/min in the polymer by this fraction and by the [3H]nucleotide specific activity. The method was successfully applied to acid extracts made from sea urchin embryos labeled with a [3H]RNA precursor.

UI	MeSH Term	Description	Entries
D007553	Isotope Labeling	Techniques for labeling a substance with a stable or radioactive isotope. It is not used for articles involving labeled substances unless the methods of labeling are substantively discussed. Tracers that may be labeled include chemical substances, cells, or microorganisms.	Isotope Labeling, Stable,Isotope-Coded Affinity Tagging,Isotopically-Coded Affinity Tagging,Affinity Tagging, Isotope-Coded,Affinity Tagging, Isotopically-Coded,Isotope Coded Affinity Tagging,Labeling, Isotope,Labeling, Stable Isotope,Stable Isotope Labeling,Tagging, Isotope-Coded Affinity,Tagging, Isotopically-Coded Affinity
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D008722	Methods	A series of steps taken in order to conduct research.	Techniques,Methodological Studies,Methodological Study,Procedures,Studies, Methodological,Study, Methodological,Method,Procedure,Technique
D010063	Ovum	A mature haploid female germ cell extruded from the OVARY at OVULATION.	Egg,Egg, Unfertilized,Ova,Eggs, Unfertilized,Unfertilized Egg,Unfertilized Eggs
D002250	Carbon Radioisotopes	Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.	Radioisotopes, Carbon
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012265	Ribonucleotides	Nucleotides in which the purine or pyrimidine base is combined with ribose. (Dorland, 28th ed)	Ribonucleoside Phosphates,Ribonucleotide,Phosphates, Ribonucleoside