AN IMPROVED METHOD FOR THE ASSAY OF PROGESTERONE BY COMPETITIVE PROTEIN BINDING

1970 ◽  
Vol 63 (2) ◽  
pp. 225-241 ◽  
Author(s):  
B. D. Reeves ◽  
M. L. A. de Souza ◽  
I. E. Thompson ◽  
E. Diczfalusy
Keyword(s):  
Protein Binding ◽  
Binding Sites ◽  
Entire Range ◽  
Improved Method ◽  
Plasma Progesterone ◽  
Extraction And Purification ◽  
Corticosteroid Binding Globulin ◽  
Competitive Protein Binding ◽  
The Individual ◽  
Range Of Values

ABSTRACT An improved method for the assay of plasma progesterone by competitive protein binding is described. The improvement is based upon rigorous control of the variables, the compensation for and standardisation of interfering factors inherent in the method and the use of a human corticosteroid binding globulin, that meets the requirements for sensitivity at levels of 1.0 ng of progesterone and below. The assessment of the reliability of the individual steps in the method as well as that of the complete method is presented. The sensitivity of the method is around 0.2 ng progesterone per ml plasma. Accuracy was measured by adding progesterone in amounts ranging from 0.0 to 1.0 ng to 1.0 ml plasma. There was a linear relationship between the progesterone added and recovered throughout the entire range of values, with a coefficient of correlation (r) of 0.94. Of 52 related steroids tested, none was found which would remain associated with progesterone following extraction and purification and which would also compete with progesterone for binding sites.

FURTHER ASSESSMENT OF THE RELIABILITY OF PROGESTERONE ASSAYS BY COMPETITIVE PROTEIN BINDING

1970 ◽  
Vol 65 (1_Suppl) ◽  
pp. S171-S187 ◽  
Author(s):  
M. L. A. de Souza ◽  
H. O. Williamson ◽  
L. O. Moody ◽  
E. Diczfalusy
Keyword(s):  
Protein Binding ◽  
Purification Procedure ◽  
Displacement Effect ◽  
Plasma Progesterone ◽  
Binding Analysis ◽  
Extraction And Purification ◽  
Competitive Protein Binding ◽  
Proper Consideration

ABSTRACT Experimental variables influencing the determination of plasma progesterone by competitive protein binding analysis have been further assessed. The precision of the method has been improved by additional mechanisation. Method interfering factors introduced by the extraction and purification procedure have been evaluated quantitatively. Another type of interfering material is present in plasma extracts from which all progesterone has been removed. The displacement effect of this material is additive to that derived from solvent and chromagram residues. Unless the various types of interfering material are taken into proper consideration, competitive protein binding methods for steroids may yield erroneous results.

Improved Measurement of Corticosteroids in Plasma and Urine by Competitive Protein-Binding Radioassay

1973 ◽  
Vol 19 (5) ◽  
pp. 511-515 ◽  
Author(s):  
Miguel Ficher ◽  
George C Curtis ◽  
V K Ganjam ◽  
Leon Joshlin ◽  
Sarah Perry
Keyword(s):  
Protein Binding ◽  
Horse Serum ◽  
Small Samples ◽  
Circadian Cycle ◽  
Lower Range ◽  
Standard Curve ◽  
Preliminary Purification ◽  
Corticosteroid Binding Globulin ◽  
Competitive Protein Binding

Abstract In the assay of corticosteroids in plasma and urine by competitive protein binding, the use of horse serum or plasma as a source of assay protein gives better sensitivity and somewhat better specificity for cortisol than do previously described procedures. Five to 10 µl of plasma unknown or 50 to 100 µl of urine unknown can be used. Precision for the standard curve is 0.12 ng in the range 0-2.00 ng, and accuracy, measured as the amount of added cortisol recovered from plasma, is about 91%. Because of the improved specificity, the need for preliminary purification by chromatography is decreased for some purposes. The same corticosteroid-binding globulin and standard curve can be used for assaying corticosteroids in urine or plasma. The procedure may be useful for unusually small samples or if discriminations within the lower range of physiological concentrations are needed, as in work with infants and neonates or in the study of small adrenal secretory pulses, such as those occurring at the nadir of the circadian cycle.

EVALUATION OF A RAPID METHOD FOR THE MEASUREMENT OF PLASMA PROGESTERONE BY COMPETITIVE PROTEIN BINDING

1970 ◽  
Vol 46 (3) ◽  
pp. 369-377 ◽  
Author(s):  
B. T. MARTIN ◽  
B. A. COOKE ◽  
W. P. BLACK
Keyword(s):  
Menstrual Cycle ◽  
Protein Binding ◽  
Ethyl Acetate ◽  
Rapid Method ◽  
Chromatographic Separation ◽  
Good Accuracy ◽  
Human Subjects ◽  
Plasma Progesterone ◽  
Competitive Protein Binding ◽  
Paper Chromatographic Separation

SUMMARY A competitive protein-binding method for the measurement of progesterone in plasma of human subjects was investigated. The purification steps necessary to achieve good accuracy, precision and specificity were determined. It was found that one paper chromatographic separation of unwashed ethyl acetate plasma extracts was sufficient, providing that the sample contains a minimum of 1 ng. progesterone. Water blank values equivalent to 0·05 ng. progesterone were consistently obtained. The concentrations of progesterone found in plasma during the follicular and luteal phases of the menstrual cycle and in male plasma were 0·14 ± 0·14, 0·82 ± 0·74 and 0·022 ± 0·015 (s.d.) μg./100 ml., respectively.

A SIMPLIFIED PROCEDURE FOR THE ASSAY OF PROGESTERONE

1970 ◽  
Vol 65 (1_Suppl) ◽  
pp. S188-S203 ◽  
Author(s):  
Elof D. B. Johansson
Keyword(s):  
Protein Binding ◽  
Petroleum Ether ◽  
Luteal Phase ◽  
Plasma Progesterone ◽  
Ether Extraction ◽  
Competitive Protein Binding ◽  
One Year ◽  
Simplified Procedure ◽  
Layer Chromatography

ABSTRACT During one year 8000 determinations of plasma progesterone have been made, using a simple petroleum ether extraction of the plasma followed by competitive protein binding analysis. The selection of the petroleum ether is crucial for the specificity, which is acceptable for the determination of progesterone during the luteal phase of the menstrual cycle and during pregnancy. The limit of sensitivity is 0.1 ng. Only 0.25 ml of plasma is needed for the determination during the luteal phase and 0.05 to 0.10 ml during pregnancy. One technician can assay 20 samples in one day with good accuracy and a precision of 7.9 per cent in the most favourable range of measurements. In research projects involving drugs the influence of these drugs on the competitive protein binding system has to be tested. Some of the samples should be further purified by thin layer chromatography as a constant check on the specificity for progesterone.

An Improved Method for Identifying Specific DNA-Protein-Binding Sites In Vitro

2017 ◽  
Vol 59 (2-3) ◽  
pp. 59-65
Author(s):  
Liangyan Wang ◽  
Huizhi Lu ◽  
Yunguang Wang ◽  
Su Yang ◽  
Hong Xu ◽  
...  
Keyword(s):  
Protein Binding ◽  
Binding Sites ◽  
Improved Method ◽  
Protein Binding Sites

THE SITE OF PROGESTERONE PRODUCTION IN EARLY PREGNANCY

1971 ◽  
Vol 67 (2) ◽  
pp. 353-361 ◽  
Author(s):  
Tore H:son Holmdahl ◽  
Elof D. B. Johansson ◽  
Leif Wide
Keyword(s):  
Protein Binding ◽  
Corpus Luteum ◽  
Early Pregnancy ◽  
Plasma Levels ◽  
Disappearance Rate ◽  
Plasma Progesterone ◽  
Progesterone Production ◽  
Vacuum Aspiration ◽  
Competitive Protein Binding

ABSTRACT The disappearance of progesterone* and HCG from the plasma was measured following therapeutic abortions in 17 patients from the seventh to the sixteenth week of pregnancy. Between the seventh and the twelfth week of gestation the evacuation of the uterine contents was performed by vacuum aspiration, and from the thirteenth week onwards abdominal hysterotomy was performed. Plasma progesterone was assayed using a competitive protein binding technique, while plasma HCG was determined by a radioimmunosorbent assay. After the evacuation of the uterine contents in the early pregnancy cases (weeks 7–8) the plasma levels of progesterone remained elevated much longer than in the later stages of pregnancy (weeks 12–16), thus suggesting that the corpus luteum graviditatis was the main source of progesterone in the first group, while in the last group the placenta was the main source of progesterone production. When comparing the earlier and later cases of pregnancy, the disappearance rate of plasma HCG remained essentially unaltered. From the results obtained, it seems likely that the transition from the ovarian to the placental production of progesterone occurs during the ninth to eleventh weeks of pregnancy.

scholarly journals Selected Factors that Affect the Measurement of Plasma Progesterone Concentrations in Pregnant Ewes

1974 ◽  
Vol 27 (6) ◽  
pp. 659 ◽  
Author(s):  
AR Gleeson ◽  
GD Thorburn
Keyword(s):  
Protein Binding ◽  
Diurnal Variation ◽  
Significant Positive Correlation ◽  
Plasma Samples ◽  
Elevated Plasma ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Peripheral Plasma ◽  
Competitive Protein Binding

A competitive protein-binding technique was used to measure progesterone concentrations in the peripheral plasma of pregnant ewes. Neither haemolysis of blood nor thawing of plasma samples affected plasma progesterone concentration. Blood samples should be chilled immediately upon collection but subsequent to centrifugation immediate chilling of the plasma samples is not critical. No consistent diurnal variation in progesterone concentrations was evident but there was large apparently random day-to-day variation in progesterone concentrations for any ewe. Although a significant positive correlation was found between endogenous progesterone and corticosteroid concentrations, the present study failed to correlate experimentally elevated plasma corticosteroid concentrations with progesterone concentrations. Progesterone concentrations varied greatly between ewes at the same stage of pregnancy.

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