Enzyme immunoassay of thyroxin-binding globulin.

1982 ◽  
Vol 28 (12) ◽  
pp. 2408-2411 ◽  
Author(s):  
K Miyai ◽  
M Ito ◽  
N Hata
Keyword(s):  
Pregnant Women ◽  
Enzyme Immunoassay ◽  
Normal Subjects ◽  
Sample Volume ◽  
Coefficients Of Variation ◽  
Analytical Recovery ◽  
The Mean ◽  
Free Serum ◽  
Test Serum ◽  
Measurable Range

Abstract We describe a new double-antibody enzyme radioimmunoassay for thyroxin-binding globulin (TBG) in serum. A TBG-beta-D-galactosidase complex was prepared with m-maleimidobenzoyl N-hydroxysuccinimide ester. The mean analytical recovery of TBG added to serum was 99%, sample volume and TBG value were linearly related, and values for TBG determined by this method and those determined by radioimmunoassay correlated well (r = 0.98). Coefficients of variation averaged 7.6% within assay, 6.6% between assay. The measurable range of TBG in the serum was 3.3 to 52 mg/L, but higher TBG concentrations could be measured by diluting the test serum with TBG-free serum. Mean (and SD) serum TBG concentrations as determined by this method were as follows: for 20 normal subjects, 21.2 (3.7) mg/L; for 10 pregnant women, 50.1 (9.5 mg/L; and for 10 patients with TBG deficiency, not detectable.

Enzyme immunoassay of free thyroxin in dried blood samples on filter paper.

1985 ◽  
Vol 31 (5) ◽  
pp. 750-753 ◽  
Author(s):  
N Hata ◽  
K Miyai ◽  
M Ito ◽  
Y Endo ◽  
Y Iijimi ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Filter Paper ◽  
Room Temperature ◽  
Normal Subjects ◽  
Blood Samples ◽  
Double Antibody ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Measurable Range

Abstract We describe a double-antibody enzyme immunoassay for determination of free thyroxin (FT4) in dried blood samples on filter paper, with use of a T4-beta-D-galactosidase complex. The measurable range of FT4 concentration in two 3-mm blood discs, each of which contained about 2.7 microL of blood, was 1.9 to 93 ng/L, as determined by comparison with concentrations of FT4 in known serum standards. FT4 in blood samples dried on filter paper was stable for at least four weeks when kept dry at -20 degrees C, room temperature, or 37 degrees C. The mean coefficients of variation were 7.6% (within assay) and 6.4% (between assays). Results for FT4 by this method correlated well with those for serum determined by radioimmunoassay (r = 0.98). The proposed method can be used to differentiate persons with hyper- and hypothyroidism from normal subjects and those with abnormal concentrations of thyroxin-binding globulin. The procedure seems suited for screening studies.

Enzyme immunoassay of free thyroxin in serum.

1984 ◽  
Vol 30 (10) ◽  
pp. 1682-1685 ◽  
Author(s):  
M Ito ◽  
K Miyai ◽  
K Doi ◽  
H Mizuta ◽  
N Amino
Keyword(s):  
Pregnant Women ◽  
Enzyme Immunoassay ◽  
Equilibrium Dialysis ◽  
Normal Adult ◽  
Double Antibody ◽  
Low Concentrations ◽  
The Mean ◽  
Measurable Range

Abstract We describe a double-antibody enzyme immunoassay for free thyroxin (FT4) in serum with use of beta-D-galactosidase conjugated to thyroxin. The method is uninfluenced by thyroxin-binding globulin or albumin. Values for FT4 so determined correlated well with those determined by radioimmunoassay (r = 0.98) and equilibrium dialysis (r = 0.89). The mean variability (CV) within and between assays was 7.4% and 7.6%, respectively. The measurable range of FT4 in serum was 2.8 to 109 ng/L. The FT4 concentrations in serum as determined by this method were 8.4 to 15.5 ng/L for 26 normal adult subjects; 26 to greater than 109 ng/L for 10 patients with hyperthyroidism; less than 2.8 to 8.0 ng/L for seven patients with hypothyroidism; 7.3 to 15.8 ng/L for eight pregnant women; and 12.2 and 13.5 ng/L for two patients with low concentrations of thyroxin-binding globulin.

Double-antibody enzyme immunoassay applied to human alpha 1-fetoprotein.

1976 ◽  
Vol 22 (2) ◽  
pp. 198-204 ◽  
Author(s):  
L Belanger ◽  
D Hamel ◽  
D Dufour ◽  
M Pouliot
Keyword(s):  
Pregnant Women ◽  
Enzyme Immunoassay ◽  
Dose Response ◽  
Present Method ◽  
Response Curve ◽  
Dose Response Curve ◽  
Clinical Samples ◽  
Double Antibody ◽  
Coefficients Of Variation ◽  
Analytical Recovery

Abstract We report the development of a double-antibody system for enzyme immunoassay of human alpha 1-fetoprotein. Equilibrium and sequential saturation procedures were evaluated and compared with a similar double-antibody radioimmunoassay. With our method, 3 mug of alpha 1-fetoprotein per liter can be detected. The dose-response curve covers a 100-fold range of analyte concentrations. Within-run and between-run coefficients of variation are respectively 6.9% and 10.0%. Analytical recovery of added antigen is 99.5 +/- 10.6%. Results are routinely obtained in 24 h but can be obtained in less than 8 h. Alpha 1-fetoprotein was measured in a variety of clinical samples, including sera from 488 pregnant women. The advantages of the present method over radioimmunoassay and other enzyme immunoassay procedures are discussed.

Effect of stripping thyroxin from thyroxin-binding globulin on the measurement of free thyroxin in serum by equilibrium dialysis and by radioimmunoassay

1990 ◽  
Vol 36 (2) ◽  
pp. 313-318 ◽  
Author(s):  
T Nakagawa ◽  
K Matsumura ◽  
K Takeda ◽  
N Shinoda ◽  
A Matsuda ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Equilibrium Dialysis ◽  
Normal Subjects ◽  
Sample Volume ◽  
Dilution Factor ◽  
Free T4 ◽  
Mean Values ◽  
Patient Groups ◽  
The Mean ◽  
Influence Measurement

Abstract In considering factors that might influence measurement of free thyroxin (T4), we evaluated the proportion (%) of T4 that could be stripped from thyroxin-binding globulin (TBG). The percentage of free T4 was measured in serially diluted sera from four normal subjects, four patients with hyperthyroidism or hypothyroidism, four pregnant women, and four malnourished subjects with low TBG. The critical percentage of stripping was determined by the product of the percentage free T4 and the critical dilution factor (the point where the percentage free T4 began to decrease). The mean values obtained for the respective patient groups--6.38%, 2.76%, 16.73%, 9.75%, and 4.28%--were proved to be related to the rate of saturation of TBG with T4. Values for percentage stripping determined with the "GammaCoat two-step RIA" and the "LiquiSol RIA" were well within the critical percentage stripping by equilibrium dialysis, except in the case of low-TBG serum as measured by LiquiSol RIA. Free T4 concentration as measured by LiquiSol RIA decreased as sample volume decreased. These findings were ascribed to the relatively high values for percentage stripping in the LiquiSol RIA, which led to erroneously low values for free T4.

Enzyme immunoassay of free triiodothyronine in serum.

1987 ◽  
Vol 33 (1) ◽  
pp. 172-176 ◽  
Author(s):  
N Hata ◽  
K Miyai ◽  
Y Endo ◽  
Y Iijima ◽  
Y Doi ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Enzyme Immunoassay ◽  
Solid Phase ◽  
Equilibrium Dialysis ◽  
Reference Interval ◽  
Normal Range ◽  
Free Triiodothyronine ◽  
Normal Limits ◽  
The Mean ◽  
Measurable Range

Abstract In this new solid-phase antibody enzyme immunoassay for free triiodothyronine (FT3) in serum, beta-D-galactosidase conjugated to triiodothyronine is used. Results are uninfluenced by physiological concentrations of thyroxin-binding globulin or albumin. Results correlate well with those determined by equilibrium dialysis (r = 0.95). The mean CVs within and between assays were 6.1 and 9.5%, respectively. The measurable range of FT3 in serum is 0.7 to 26 ng/L; the normal reference interval is 1.9 to 8.9 ng/L. Concentrations of FT3 in serum of patients with hyperthyroidism were high; those of patients with hypothyroidism were within normal limits or low, and those of patients with congenitally decreased or increased TBG were within the normal range. In normal pregnant women, concentrations of FT3 as determined by radioimmunoassay correlated with those of albumin, declining as pregnancy progressed, but FT3 values determined by the proposed method or equilibrium dialysis were within the normal range and did not change during pregnancy.

Simplified radioimmunoassay of bradykinin in human plasma.

1980 ◽  
Vol 26 (3) ◽  
pp. 429-432
Author(s):  
P S Verma ◽  
P E Lorenz ◽  
G E Sander
Keyword(s):  
Molecular Mass ◽  
Human Plasma ◽  
Normal Values ◽  
Normal Subjects ◽  
Single Step ◽  
Relative Molecular Mass ◽  
Blood Samples ◽  
Analytical Recovery ◽  
Assay Tube ◽  
The Mean

Abstract A greatly simplified radioimmunoassay for bradykinin in human plasma is described. Current techniques require multiple chromatographic steps or extraction procedures with analytical recoveries of bradykinin of often less than 60%. We present a method in which bradykinin is separated from components of higher relative molecular mass (including kininogens) in a single step, by use of a column of Sephadex G-25 medium (PD-10). The mean analytical recovery of tritiated bradykinin added to plasma is 85.5% (SD, 3.5%). The sensitivity of this radioimmunoassay is 25 pg per assay tube, equivalent to 125 ng per liter of plasma. Twenty to 30 blood samples may be completely processed and assayed within 6 h. As determined with this technique, concentrations of bradykinin in plasma from apparently normal subjects ranged from 2.5 to 5.2 microgram/L (mean 4.2, SD 1.1 microgram/L); these values are consistent with previously reported normal values.

Simplified radioimmunoassay of bradykinin in human plasma.

1980 ◽  
Vol 26 (3) ◽  
pp. 429-432 ◽  
Author(s):  
P S Verma ◽  
P E Lorenz ◽  
G E Sander
Keyword(s):  
Molecular Mass ◽  
Human Plasma ◽  
Normal Values ◽  
Normal Subjects ◽  
Single Step ◽  
Relative Molecular Mass ◽  
Blood Samples ◽  
Analytical Recovery ◽  
Assay Tube ◽  
The Mean

Abstract A greatly simplified radioimmunoassay for bradykinin in human plasma is described. Current techniques require multiple chromatographic steps or extraction procedures with analytical recoveries of bradykinin of often less than 60%. We present a method in which bradykinin is separated from components of higher relative molecular mass (including kininogens) in a single step, by use of a column of Sephadex G-25 medium (PD-10). The mean analytical recovery of tritiated bradykinin added to plasma is 85.5% (SD, 3.5%). The sensitivity of this radioimmunoassay is 25 pg per assay tube, equivalent to 125 ng per liter of plasma. Twenty to 30 blood samples may be completely processed and assayed within 6 h. As determined with this technique, concentrations of bradykinin in plasma from apparently normal subjects ranged from 2.5 to 5.2 microgram/L (mean 4.2, SD 1.1 microgram/L); these values are consistent with previously reported normal values.

Enzyme immunoassay of carbamazepine with a centrifugal analyzer.

1979 ◽  
Vol 25 (2) ◽  
pp. 295-298 ◽  
Author(s):  
D A Lacher ◽  
R Valdes ◽  
J Savory
Keyword(s):  
Enzyme Immunoassay ◽  
Sample Volume ◽  
Gas Liquid Chromatography ◽  
Good Precision ◽  
Concentration Data ◽  
Kinetic Rate ◽  
Analytical Recovery ◽  
Assay Time ◽  
Quantitative Results ◽  
Carbamazepine Concentration

Abstract We describe a rapid enzyme immunoassay for carbamazepine with a centrifugal analyzer (Rotochem IIA-36). Reagent costs are reduced fourfold while good precision and sensitivity are maintained. Sample volume is 10 microliter, and as many as 28 patients' sera can be measured during an assay time of 225 s. Assay temperature is 30 degrees C, the wavelength 340 nn. Linearity is excellent for a carbamazepine concentration range of 1 to 12 mg/L; analytical recovery is quantitative. Results correlate well with those by liquid- and gas-liquid chromatography. Absorbance rates for each carbamazepine concentration are acquired by a multi-point kinetic rate program and a computer program provides a logit-log transformation of absorbance rate vs. concentration data for final calculations in the assay. Hemoglobin interference precludes analysis of severely hemolyzed specimens.

THE "EFFECTIVE THYROXINE RATIO" – NEW IN VITRO TEST OF THYROID FUNCTION AND ITS CORRELATION WITH FREE THYROXINE

1974 ◽  
Vol 76 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Janusz Nauman ◽  
Alicja Nauman
Keyword(s):  
Pregnant Women ◽  
Normal Subjects ◽  
Free Thyroxine ◽  
In Vitro Test ◽  
High Reproducibility ◽  
Vitro Test ◽  
The Mean ◽  
Hypothyroid Patients ◽  
Hyperthyroid Patients

ABSTRACT The effective thyroxine ratio (ETR) and absolute concentration of free thyroxine (AFT4) were estimated in the sera of 31 normal subjects, 27 hyperthyroid patients, 12 hypothyroid patients and 21 euthyroid pregnant women. The mean ETR value in the controls was 1.0 ± 0.18, in the hyperthyroid patients 1.31 ± 0.25, in the hypothyroid patients 0.71 ± 0.21 and in normal pregnant women 0.99 ± 0.24. The mean AFT4 in the normal subjects was 3.0 ± 0.53 ng/100 ml, in the hyperthyroid patients 9.49 ± 2.44 ng/ 100 ml, in the hypothyroid patients 0.58 ± 0.15 ng/100 ml and in the pregnant women 2.84 ± 0.63 ng/100 ml, respectively. High reproducibility of ETR and a significant positive correlation between ETR and AFT4 with r = 0.96 suggest that ETR might be a suitable in vitro test for routine clinical evaluation of the thyrometabolic state.

A new enzyme immunoassay for prolactin in serum or plasma

1990 ◽  
Vol 36 (1) ◽  
pp. 76-80 ◽  
Author(s):  
R Babiel ◽  
P Willnow ◽  
M Baer ◽  
M van Gent ◽  
V Ehrhardt
Keyword(s):  
Polyethylene Glycol ◽  
Horseradish Peroxidase ◽  
Enzyme Immunoassay ◽  
World Health ◽  
Placental Lactogen ◽  
Human Placental Lactogen ◽  
Analytical Recovery ◽  
Human Prolactin ◽  
Health Organization ◽  
Measurable Range

Abstract This enzyme immunoassay (EIA) of human prolactin (hPRL) involves incubation of sample and anti-hPRL antibodies conjugated to horseradish peroxidase (EC 1.11.1.7) in tubes coated with a second antibody to hPRL. The test can be performed within 60 min. No reaction of the antibodies with human placental lactogen and human somatotropin is detectable. The presence of detergent allows assay of both serum and plasma. Precision was improved by including polyethylene glycol in the reaction mixture. To optimize analytical recovery, we added protease inhibitor. Assay of the EIA standards shows good correlation with results for World Health Organization reference preparations. The measurable range is 1 to 400 micrograms/L. Intra- and interassay CVs are about 5%. Comparisons with two RIAs and two other EIAs show reasonably good correlations. The components of our EIA are stable for 18 months.

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