Biomaterial Database

Serum testosterone determination by mass fragmentography. 1975

I Björkhem, and O Lantto, and L Svensson

A mass fragmentographic reference method for the determination of plasma or serum testosterone is described. A fixed amount of [4--14C]testosterone (usually 10 ng) is added to a fixed amount of serum (usually 1 ml) and extracted with ether. The ether extract is purified by means of thin-layer chromatography. The purified testosterone is converted into the di-trimethylsilyl derivative by treatment with trimethylsilylimidazole. The amount of unlabeled testosterone is determined from the ratio between the recordings at m/e 432 and 434, obtained after analysis with a combined gas chromatograph-mass spectrometer equipped with a MID-unit (multiple ion detector). The two ions used correspond to the molecular peak in the mass spectrum of unlabeled and 4--14C-labeled testosterone, respectively. The relative standard deviation of the method was about 2.7 percent. The method was compared with a radioimmunoassay technique. There was a good correlation and the regression coefficient was about 0.83. A diurnal rhythm in testosterone secretion was confirmed both with the mass fragmentographic technique and with radioimmunoassay.

UI	MeSH Term	Description	Entries
D007093	Imidazoles	Compounds containing 1,3-diazole, a five membered aromatic ring containing two nitrogen atoms separated by one of the carbons. Chemically reduced ones include IMIDAZOLINES and IMIDAZOLIDINES. Distinguish from 1,2-diazole (PYRAZOLES).
D008297	Male		Males
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
D010949	Plasma	The residual portion of BLOOD that is left after removal of BLOOD CELLS by CENTRIFUGATION without prior BLOOD COAGULATION.	Blood Plasma,Fresh Frozen Plasma,Blood Plasmas,Fresh Frozen Plasmas,Frozen Plasma, Fresh,Frozen Plasmas, Fresh,Plasma, Blood,Plasma, Fresh Frozen,Plasmas,Plasmas, Blood,Plasmas, Fresh Frozen
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
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
D002849	Chromatography, Gas	Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.	Chromatography, Gas-Liquid,Gas Chromatography,Chromatographies, Gas,Chromatographies, Gas-Liquid,Chromatography, Gas Liquid,Gas Chromatographies,Gas-Liquid Chromatographies,Gas-Liquid Chromatography
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D005069	Evaluation Studies as Topic	Works about studies that determine the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies.	Critique,Evaluation Indexes,Evaluation Methodology,Evaluation Report,Evaluation Research,Methodology, Evaluation,Pre-Post Tests,Qualitative Evaluation,Quantitative Evaluation,Theoretical Effectiveness,Use-Effectiveness,Critiques,Effectiveness, Theoretical,Evaluation Methodologies,Evaluation Reports,Evaluation, Qualitative,Evaluation, Quantitative,Evaluations, Qualitative,Evaluations, Quantitative,Indexes, Evaluation,Methodologies, Evaluation,Pre Post Tests,Pre-Post Test,Qualitative Evaluations,Quantitative Evaluations,Report, Evaluation,Reports, Evaluation,Research, Evaluation,Test, Pre-Post,Tests, Pre-Post,Use Effectiveness
D005260	Female		Females