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

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.

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

Acta Endocrinologica ◽

10.1530/acta.0.0630225 ◽

1970 ◽

Vol 63 (2) ◽

pp. 225-241 ◽

Cited By ~ 12

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.

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A simple procedure for the combined determination of plasma estrogen and androgen concentrations by competitive protein binding analysis

Journal of Steroid Biochemistry ◽

10.1016/0022-4731(72)90064-7 ◽

1972 ◽

Vol 3 (4) ◽

pp. 725-733 ◽

Cited By ~ 6

Author(s):

Giuseppe Concolino ◽

Antonietta Marocchi

Keyword(s):

Protein Binding ◽

Simple Procedure ◽

Binding Analysis ◽

Competitive Protein Binding

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The determination of maternal and foetal rat plasma corticosterone concentration in late pregnancy by competitive protein binding analysis

Journal of Steroid Biochemistry ◽

10.1016/0022-4731(83)90138-3 ◽

1983 ◽

Vol 18 (5) ◽

pp. 601-606 ◽

Cited By ~ 8

Author(s):

D. Pechinot ◽

A. Cohen

Keyword(s):

Protein Binding ◽

Late Pregnancy ◽

Plasma Corticosterone ◽

Rat Plasma ◽

Corticosterone Concentration ◽

Binding Analysis ◽

Foetal Rat ◽

Competitive Protein Binding

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A SIMPLIFIED PROCEDURE FOR THE ASSAY OF PROGESTERONE

Acta Endocrinologica ◽

10.1530/acta.0.065s188 ◽

1970 ◽

Vol 65 (1_Suppl) ◽

pp. S188-S203 ◽

Cited By ~ 26

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.

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