Protein-Binding Assay for Plasma Testosterone, after Purification by Column Partition Chromatography

1974 ◽  
Vol 20 (4) ◽  
pp. 430-435 ◽  
Author(s):  
E D Horgan ◽  
W J Riley
Keyword(s):  
Protein Binding ◽  
Plasma Testosterone ◽  
Good Precision ◽  
Third Trimester ◽  
Protein Binding Assay ◽  
Competitive Protein Binding ◽  
Menstruating Women ◽  
The Mean ◽  
Normal Men ◽  
Practicable Method

Abstract We describe a relatively simple, specific, and practicable method for measuring plasma testosterone by competitive protein-binding analysis. An ether extract is purified by a single chromatographic step on a micro-scale Celite—ethylene glycol column. Serum from women in the third trimester of pregnancy is used as the binding protein, and an ammonium sulfate precipitation step is used to separate the free and protein-bound testosterone. The method has a consistently low blank [0.59 ± 0.26 (SD) pmol/sample] and shows good precision. The mean testosterone concentration in normal men and menstruating women was 17.1 ± 4.0 (SD) and 1.2 ± 0.4 (SD) nmol/liter, respectively.

Competitive Protein-Binding Assay for 25-Hydroxycholecalciferol

1974 ◽  
Vol 46 (2) ◽  
pp. 231-240 ◽  
Author(s):  
S. Edelstein ◽  
M. Charman ◽  
D. E. M. Lawson ◽  
E. Kodicek
Keyword(s):  
Protein Binding ◽  
Binding Assay ◽  
Rat Serum ◽  
Male And Female ◽  
Normal Volunteers ◽  
Protein Binding Assay ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
The Mean ◽  
25 Hydroxycholecalciferol

1. A competitive protein-binding assay for plasma 25-hydroxycholecalciferol was developed, using Sephadex LH-20 columns for the isolation of the sterol and a partially purified protein from rat serum as the binding protein. 2. The mean plasma 25-hydroxycholecalciferol in eighteen male and female normal volunteers was 38 ± SD 14 pmol/ml (15–2 ± 5–6 ng/ml). 3. Levels of 25-hydroxycholecalciferol in plasma of four male volunteers maintained for 2 months on a diet supplemented with 26·1 nmol (10 μg) of cholecalciferol a day were found to be significantly higher. 4. High correlation was established between plasma 25-hydroxycholecalciferol values obtained by the competitive protein-binding assay and values obtained by bioassay.

RELIABILITY OF PLASMA TESTOSTERONE ASSAYS BY COMPETITIVE PROTEIN BINDING METHODS

1970 ◽  
Vol 65 (1_Suppl) ◽  
pp. S257-S274 ◽  
Author(s):  
C. A. Nugent ◽  
D. Mayes
Keyword(s):  
Protein Binding ◽  
Binding Assay ◽  
Binding Protein ◽  
Plasma Testosterone ◽  
Protein Binding Assay ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
Double Isotope

ABSTRACT This report examines the reliability of different methods for competitive protein binding assay of plasma testosterone. Most of the methods give results similar to those reported by the most reliable of the competitive protein binding methods and by established double isotope derivative methods. In a few instances poor reliability was demonstrated. However, the reliability of the remaining methods usually had not been investigated thoroughly. An adequate examination of accuracy was one of the most frequent omissions in the investigation of the reliability of these methods. Differences between direct standards and samples containing known amounts of testosterone purified in the same manner as unknown samples can develop easily in competitive protein binding methods. These differences may be caused by substances other than the steroid being measured or by alteration of the labelled or unlabelled steroid. The interfering substance or altered steroid may be present before or appear during or after purification. The impurity may or may not be removed in purification and it may or may not bind with the binding protein. To detect these types of errors, accuracy studies should be done throughout the range of concentrations in which it is expected to apply the method.

Quantitation of Plasma Testosterone by Improved Competitive Protein-Binding Technique

1970 ◽  
Vol 16 (2) ◽  
pp. 111-117 ◽  
Author(s):  
J A Demetriou ◽  
F G Austin
Keyword(s):  
Protein Binding ◽  
Binding Assay ◽  
Plasma Testosterone ◽  
Normal Female ◽  
Adrenal Hyperplasia ◽  
Protein Binding Assay ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
Male Subjects ◽  
Double Isotope

Abstract A method is described for quantitation of testosterone in plasma from females and males. The principal operations of extraction, chromatographic fractionation, and competitive protein-binding assay can be completed for eight duplicate samples in a single day. Experimental data used in the development of the test and the rationale for the specific operations and conditions are presented. The specificity of the method was established by comparing plasma testosterone concentrations determined by the double isotope derivative technique. Concentrations are reported for normal female and male subjects, and for patients with hirsutism, adrenal hyperplasia, Klinefelter’s syndrome, and other endocrine conditions.

THE EFFECT OF MESTEROLONE ADMINISTRATION TO NORMAL MEN ON THE PITUITARY-TESTICULAR FUNCTION

1974 ◽  
Vol 77 (2) ◽  
pp. 380-386 ◽  
Author(s):  
A. Aakvaag ◽  
S. B. Strømme
Keyword(s):  
Protein Binding ◽  
Testosterone Level ◽  
Plasma Levels ◽  
Mean Value ◽  
Plasma Testosterone ◽  
Testicular Function ◽  
Plasma Testosterone Level ◽  
Before And After ◽  
The Mean ◽  
Normal Men

ABSTRACT Mesterolone (1α-methyl-5α-dihydrotestosterone) has been given to 10 normal men, age 24–27 years, and the effect on the plasma levels of ICSH, FSH and testosterone has been studied. No effect on the plasma levels of ICSH and FSH could be detected. After 4 weeks on 75 mg mesterolone per day a significant (P < 0.01) drop in the mean value for plasma testosterone level was observed, 5.2 to 4.0 ng/ml. After another 4 weeks on 150 mg mesterolone per day a further decrease to 3.5 ng/ml was found. During mesterolone administration the protein binding of testosterone in plasma was significantly reduced, and it appeared that the level of free (non-protein bound) testosterone in diluted plasma remained unchanged, 0.37 and 0.41 ng/ml, before and after mesterolone administration respectively. The results suggest that mesterolone given in doses of 75 and 150 mg/day to normal men does not suppress the pituitary ICSH production or the testicular testosterone production.

PROGESTERONE LEVELS IN PERIPHERAL PLASMA DURING THE LUTEAL PHASE OF THE NORMAL HUMAN MENSTRUAL CYCLE MEASURED BY A RAPID COMPETITIVE PROTEIN BINDING TECHNIQUE

1969 ◽  
Vol 61 (4) ◽  
pp. 592-606 ◽  
Author(s):  
Elof D. B. Johansson
Keyword(s):  
Protein Binding ◽  
Luteal Phase ◽  
Good Precision ◽  
Progesterone Concentration ◽  
Normal Human ◽  
Competitive Protein Binding ◽  
The Mean ◽  
Human Menstrual Cycle ◽  
Mean Concentration ◽  
Plateau Level

ABSTRACT The competitive protein binding technique for the measurement of progesterone has been further simplified for clinical use. Only 0.25 ml of plasma is needed for the determination during the luteal phase. One technician can assay 20 samples in one day with good precision and accuracy. The progesterone concentration in 20 normal human menstrual cycles was studied. During the follicular phase a mean concentration of 0.32 ± 0.25 (s) ng/ml plasma was found. At the mid-cycle peak of the total oestrogens the progesterone concentration started to rise and reached a plateau between 10–20 ng/ml 4 to 6 days later. From the plateau level, the concentration fell rapidly to less than 1 ng/ml at the onset of menstrual bleeding. The mean luteal phase lasted for 14.15 ± 1.05 (s) days.

scholarly journals Comparison of a Fluorimetric Method and a Competitive Protein Binding Assay Kit for the Determination of Plasma Hydroxycorticosteroids

1975 ◽  
Vol 12 (1-6) ◽  
pp. 160-162 ◽  
Author(s):  
Marion Gore ◽  
Eva Lester
Keyword(s):  
Protein Binding ◽  
Binding Assay ◽  
Normal Subjects ◽  
Fluorimetric Method ◽  
Protein Binding Assay ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
The Mean ◽  
Selenium 75

A new competitive protein binding (C.P.B.) assay kit for the determination of plasma hydroxycorticosteroids which uses a gamma emitting isotope, selenium-75, to label the Cortisol was compared with a fluorimetric method in use in a routine laboratory. The mean plasma corticosteroid level in a group of 54 normal subjects was found to be lower with the C.P.B. kit than with the fluorimetric method. The correlation coefficient between the two methods in 131 specimens from healthy subjects and patients under investigation for pituitary or adrenocortical disorders was + 0.92. The precision of the two methods was similar.

A SIMPLE COMPETITIVE PROTEIN-BINDING ASSAY FOR ADENOSINE-3′,5′-MONOPHOSPHATE IN PLASMA AND URINE

1976 ◽  
Vol 81 (1) ◽  
pp. 208-214 ◽  
Author(s):  
S. Nistrup Madsen ◽  
I. Badawi ◽  
L. Skovsted
Keyword(s):  
Protein Binding ◽  
Binding Assay ◽  
Plasma Samples ◽  
Protein Binding Assay ◽  
Urinary Content ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
The Mean

ABSTRACT A modified competitive protein-binding assay for the measurement of adenosine-3′,5′-monophosphate is desribed. The procedure allows measurement of adenosine-3′,5′-monophosphate in unextracted plasma samples. The mean plasma values in 25 normal, fasting and ambulatory subjects were 22.7 ± 4.7 pmol/ml (mean ± sd) (range 13–31 pmol/ml. The mean urinary content was 3.2 ± 1.0 μmol per g creatinine (mean ± sd) (n=24).

RELIABILITY CRITERIA FOR SATURATION ANALYSIS OF STEROIDS BY COMPETITIVE PROTEIN BINDING

1970 ◽  
Vol 65 (1_Suppl) ◽  
pp. S61-S78 ◽  
Author(s):  
Billy D. Reeves ◽  
David W. Calhoun
Keyword(s):  
Protein Binding ◽  
Assay Method ◽  
Statistical Control ◽  
Protein Binding Assay ◽  
Competitive Protein Binding Assay ◽  
System 2 ◽  
Competitive Protein Binding ◽  
Single Method ◽  
Assay Design ◽  
Proper Perspective

ABSTRACT This communication is an attempt to delineate and define reliability criteria for saturation analysis of steroids by competitive protein binding assay. The discussion of these criteria evolved from three major considerations of assay method that help to place the ultimate criterion of accuracy in proper perspective. These major considerations are: 1) the measurement system, 2) the assay design and 3) the calculations and statistical control. Such an approach permits an evaluation, both relative and absolute, for a single method or for multiple methods.

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