An accelerated enzyme immunoassay for human choriogonadotropin in urine, involving reflow of specimen through capillary tubes.

1987 ◽  
Vol 33 (4) ◽  
pp. 498-501 ◽  
Author(s):  
H M Chandler ◽  
S A Fuller ◽  
C H Nakagawa ◽  
P A Nagainis ◽  
J G Hurrell
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Enzyme Immunoassay ◽  
Test Specimen ◽  
Capillary Tube ◽  
Test Procedure ◽  
Beta Subunit ◽  
Sensitive Assay ◽  
Substrate Solution ◽  
Human Choriogonadotropin

Abstract A very rapid and sensitive assay for human choriogonadotropin (hCG) has been developed involving two beta-subunit-specific monoclonal antibodies. In the assay the test specimen is passed backward and forward (reflow) through a monoclonal-antibody-coated capillary tube for 1 min, then incubated for 1 min with a second monoclonal antibody conjugated to urease (EC 3.5.1.5). After addition of a urease substrate solution, 10 int. units of hCG per liter can be detected visually within 5 min, which compares very favorably with other currently available hCG assay procedures. Advantages of the reflow/capillary tube assay system and optimization of the test procedure are discussed.

Evaluation of a solid-phase enzyme immunoassay for human choriogonadotropin beta subunit.

1983 ◽  
Vol 29 (11) ◽  
pp. 1964-1966 ◽  
Author(s):  
D D Davey ◽  
M M Sample ◽  
T O Oei
Keyword(s):  
Enzyme Immunoassay ◽  
Solid Phase ◽  
Cross Reactivity ◽  
Beta Subunit ◽  
Neoplastic Disease ◽  
Standard Curve ◽  
Human Choriogonadotropin ◽  
Beta Hcg ◽  
Substantial Problem ◽  
Sample Dilution

Abstract We evaluated a quantitative solid-phase enzyme immunoassay for human choriogonadotropin beta subunit (beta-HCG) with anti-beta-HCG:horseradish peroxidase conjugate, recently marketed by Abbott Laboratories. We compared results on 56 patients' serum specimens, obtained mostly for followup of neoplastic disease, with those by a competitive radioimmunoassay kit. The correlation was good, the differences being of little clinical significance. Linear regression in the low and intermediate ranges gave a slope of 0.93, a y-intercept of 0.34, and a correlation coefficient of 0.97. Precision studies yielded an interassay CV of 6.4% in the intermediate range and 13% in the low range. Sensitivity was 0.69 int. unit/L. Cross reactivity was 1 to 2% with specimens fortified with lutropin or follitropin. The only substantial problem was with linearity in the upper part of the standard curve, especially in the interval, 100-200 int. units/L. This problem is obviated by adequate sample dilution.

Two-monoclonal-antibody "sandwich"-type assay of human lutropin, with no cross reaction with choriogonadotropin.

1987 ◽  
Vol 33 (9) ◽  
pp. 1603-1607 ◽  
Author(s):  
W D Odell ◽  
J Griffin
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Detection Limit ◽  
Dose Response ◽  
Response Curve ◽  
Cross Reaction ◽  
Dose Response Curve ◽  
Low Doses ◽  
Human Choriogonadotropin ◽  
Sandwich Type

Abstract We have developed a sensitive, specific, noncompetitive sandwich-type assay for human lutropin (hLH). Two monoclonal antibodies are used, and there is no cross reaction with human choriogonadotropin (hCG) or human follitropin (hFSH), and little or none with human thyrotropin (hTSH). There also is no reaction with the free beta chains of hLH and hCG. The detection limit is less than 0.5 int. units of hLH per liter of serum, and the dose-response curve is linear between 0 and 10 int. units/L. The intra-assay CV averaged 5.4% at low doses of hLH; the interassay CV averaged 12.5%.

scholarly journals Evidence for a new rotavirus subgroup in India

1989 ◽  
Vol 102 (3) ◽  
pp. 523-530 ◽  
Author(s):  
S. K. Ghosh ◽  
T. N. Naik
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Enzyme Immunoassay ◽  
Human Rotavirus ◽  
Group A Rotaviruses ◽  
Group A ◽  
Different Parts

SUMMARYMonoclonal antibodies specific for rotavirus subgroup 1 (SG1) and subgroup 2 (SG2) were used to analyse by enzyme immunoassay (EIA) the subgroups of human rotavirus isolates obtained from three different parts of India during the period September 1985 to July 1987. We identified one isolate which failed to react with either SG1 or SG2 specific monoclonal antibodies, although it reacted well with a monoclonal antibody specific for group A rotaviruses. This finding suggests that it belongs to a new rotavirus subgroup. Further, another isolate was found to belong to SG1 although it had a ‘long’ electropherotype.

Improved measurement of free alpha subunit of glycoprotein hormones by assay with use of a monoclonal antibody.

1988 ◽  
Vol 34 (10) ◽  
pp. 2022-2025 ◽  
Author(s):  
R W Whitcomb ◽  
J S Sangha ◽  
A L Schneyer ◽  
W F Crowley
Keyword(s):  
Monoclonal Antibody ◽  
Detection Limit ◽  
Cross Reactivity ◽  
Assay System ◽  
Beta Subunit ◽  
Alpha Subunit ◽  
Glycoprotein Hormones ◽  
Sensitive Assay ◽  
Precise Information ◽  
Sensitive Method

Abstract Any exploration of the physiology of secretion of free alpha subunit of glycoprotein hormones in humans requires a sensitive assay system that shows low cross reactivity with the intact hormones (lutropin, follitropin, thyrotropin, and choriogonadotropin). We established and validated such an assay system with a monoclonal antibody for detection of free alpha subunit in serum with better sensitivity (detection limit, 30 ng/L) and less cross reactivity (0.67% with intact human lutropin) than with available polyclonal antibody methods. Thus, the specific epitope recognized by this antibody apparently is exposed only on the free or uncombined form of alpha subunit and is concealed after non-covalent combination with any beta subunit. Using Western blot analysis, we show that most of the cross reactivity is probably the result of contamination of the human lutropin standard (obtained from the National Hormone and Pituitary Program, NIH) with small amounts of free alpha subunit. With such a specific and sensitive method, it should be possible to obtain more-precise information regarding the secretion of free alpha subunit.

Epitope-selective, monoclonal-antibody-based immunoradiometric assays of predictable specificity for differential measurement of choriogonadotropin and its subunits.

1985 ◽  
Vol 31 (8) ◽  
pp. 1322-1328 ◽  
Author(s):  
S Schwarz ◽  
P Berger ◽  
G Wick
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Conformational Epitope ◽  
Alpha Subunit ◽  
Beta Subunits ◽  
Differential Measurement ◽  
Analytical Strategy ◽  
Alpha Subunits ◽  
Human Choriogonadotropin ◽  
Beta Hcg

Abstract Knowing the epitope specificities of our monoclonal antibodies (MCA) to human choriogonadotropin (hCG), we could design three classes of two-site immunoradiometric assays (IRMA): a combination of two MCA recognizing two separate alpha-epitopes (alpha-MCA) provides a system (i.e., an alpha-IRMA) that measures holo-hCG plus free alpha-subunits plus follitropin, lutropin, and thyrotropin, whereas a beta-IRMA, consisting of two beta-MCA, quantifies holo-hCG plus free beta-subunits. The amount of either of the two subunits can be calculated by subtracting the amount of holo-hCG determined in parallel in a holo-hCG-IRMA. In the latter, one of the alpha- or beta-MCA may be either cross-combined or, preferably, paired with an MCA specific for a conformational epitope. These analytical specificities, predicted from our previously established epitope map of hCG, could be experimentally verified. With these IRMAS we could demonstrate that in certain choriocarcinoma cell lines the earliest and quantitatively predominant tumor marker is the free alpha-subunit. Similar results showing an unbalanced secretion of hCG and its subunits were obtained for patients with related tumors. These findings challenge the present diagnostic practice of relying solely on "beta-hCG" radioimmunoassays and at the same time offer a novel analytical strategy.

Detection of thyroid disorders by use of basal thyrotropin values determined with an optimized "sandwich" enzyme immunoassay.

1985 ◽  
Vol 31 (2) ◽  
pp. 289-292 ◽  
Author(s):  
C Bernutz ◽  
M Kewenig ◽  
K Horn ◽  
C R Pickardt
Keyword(s):  
Monoclonal Antibodies ◽  
Enzyme Immunoassay ◽  
Limit Of Detection ◽  
Specific Binding ◽  
Thyroid Stimulating Hormone ◽  
Beta Subunit ◽  
Thyroid Disorders ◽  
Sandwich Enzyme Immunoassay ◽  
Assay Protocol ◽  
Basal Concentration

Abstract To measure the concentrations of thyrotropin (thyroid-stimulating hormone), we used the components of a commercially available two-step "sandwich" enzyme immunoassay (Enzymun-Test TSH, Boehringer Mannheim) based on the specific binding of the beta-subunit of thyrotropin by monoclonal antibodies coated on polystyrene tubes. By modifying the original assay protocol, we lowered the limit of detection to 0.18 milli-int. units/L, using a total incubation period of 22 h. With this modification we could differentiate between patients responsive to administration of thyroliberin (thyrotropin-releasing factor) and those who were non-responders, by measuring only the basal concentration of thyrotropin. Furthermore, we demonstrated a correlation between the basal concentration of thyrotropin and its increase after administration of thyroliberin (r = 0.77, n = 48).

Production of murine hybrid-hybridomas secreting bispecific monoclonal antibodies for use in urease-based immunoassays.

1988 ◽  
Vol 34 (9) ◽  
pp. 1693-1696 ◽  
Author(s):  
M Takahashi ◽  
S A Fuller
Keyword(s):  
Monoclonal Antibodies ◽  
Enzyme Immunoassay ◽  
Growth Rates ◽  
Bispecific Antibodies ◽  
Growth Media ◽  
Human Choriogonadotropin ◽  
Mouse Immunoglobulin ◽  
Immunoglobulin Subclasses ◽  
Igg1 Subclass ◽  
Hybridoma Cell Lines

Abstract To produce bispecific antibodies (BiAbs) for enzyme immunoassay (EIA) to replace antibody-enzyme conjugates, we developed a panel of 8-azaguanine/ouabain-resistant anti-urease variant hybridoma cell lines for use in hybridoma-hybridoma fusions. These variants represent mouse immunoglobulin subclasses IgM, IgG1, IgG2a, and IgG2b and have growth rates equal to those of the parental hybridomas. We fused an anti-urease-secreting variant hybridoma with an anti-human choriogonadotropin (hCG)-secreting hybridoma (both of IgG1 subclass) and selected the desired product with growth media containing hypoxanthine-aminopterin-thymidine (HAT) and ouabain. Over 95% of the resulting hybrids secreted anti-urease, and 60% of these secreted anti-hCG. The bispecific nature of secreted antibodies was demonstrated in a simultaneous EIA where BiAbs, hCG, and urease (EC 3.5.1.5) were incubated together in anti-hCG-coated microwells. As little as 25 int. units of hCG per liter could be reliably detected, which is equivalent to that for antibody-enzyme conjugates in EIA.

Enzyme immunoassay of the glycoprotein tropic hormones--choriogonadotropin, lutropin, thyrotropin--with solid-phase monoclonal antibody for the alpha-subunit and enzyme-coupled monoclonal antibody specific for the beta-subunit.

1982 ◽  
Vol 28 (9) ◽  
pp. 1862-1866 ◽  
Author(s):  
H G Wada ◽  
R J Danisch ◽  
S R Baxter ◽  
M M Federici ◽  
R C Fraser ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Room Temperature ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Beta Subunit ◽  
Alpha Subunit ◽  
Enzyme Conjugate ◽  
Capture Antibody ◽  
Assay Precision

Abstract Monoclonal antibody technology has made it possible to produce homogeneous populations of antibodies to discrete determinants on an antigen surface. We have produced monoclonal antibodies to the alpha-subunit and beta-subunits of the glycoprotein hormones choriogonadotropin, thyrotropin, and lutropin, and developed two-site simultaneous enzyme-linked immunospecific assays for these hormones. The anti-alpha-subunit monoclonal antibody was used as the solid-phase (coated tube) capture antibody for all three hormones; the anti-beta-subunit monoclonal antibodies were coupled to horseradish peroxidase (EC 1.11.1.7). Cross reactions between the closely related choriogonadotropin and lutropin were apparently greater in this method than in RIA, with use of the same antibodies. Ka of the antibodies did not appear to be as critical to sensitivity of the sandwich assay as it was for RIA. The lower limit of detection was 0.2 microgram/L after a 2-h incubation with serum sample at room temperature and a 30-min incubation with enzyme substrate at room temperature after washing away excess enzyme conjugate. Within-assay precision (CV) was very good, less than 6%.

Highly specific enzyme immunoassay for the beta-subunit of human thyrotropin with use of monoclonal antibodies.

1988 ◽  
Vol 34 (1) ◽  
pp. 98-102 ◽  
Author(s):  
Y Iijima ◽  
Y Endo ◽  
N Hata ◽  
H Fujita ◽  
M Unoki ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Solid Phase ◽  
Pituitary Tumors ◽  
Cross Reactivity ◽  
Beta Subunit ◽  
Specific Enzyme ◽  
Human Choriogonadotropin ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Hypothyroid Patients

Abstract A highly specific enzyme-linked "sandwich" immunoassay is described for determining free human thyrotropin (hTSH) beta-subunit in serum by using a anti-hTSH beta-subunit monoclonal antibody conjugated with beta-D-galactosidase (EC 3.2.1.23) and a solid phase consisting of silicone rods coated with another monoclonal antibody. We could detect as little as 0.04 ng of beta-subunit per assay. The measurable range of hTSH beta-subunit concentrations in serum was 0.4 to 50 micrograms/L. The assay demonstrated little or no cross reactivity with intact hTSH, hTSH alpha-subunit, or human choriogonadotropin. The mean CVs were 12.2% within assay, 13.9% between assay. The hTSH beta-subunit was not detectable in sera from healthy subjects, patients with hyperthyroidism, or two patients with pituitary tumors producing TSH. It was measurable (at concentrations of 0.65 to 2.70 micrograms/L) in sera from eight of 23 hypothyroid patients. In five of the hypothyroid patients examined, the concentration of hTSH beta-subunit in serum increased after administration of thyroliberin. This method may be useful in elucidating the physiological and pathological significance of the hTSH beta-subunit and in examining the function of the hypothalamus-pituitary-thyroid axis.

The Stratus immunofluorometric assay system evaluated for quantifying human choriogonadotropin in serum.

1986 ◽  
Vol 32 (7) ◽  
pp. 1402-1404 ◽  
Author(s):  
L C Rogers ◽  
S E Kahn ◽  
T H Oeser ◽  
E W Bermes
Keyword(s):  
Monoclonal Antibodies ◽  
Regression Equation ◽  
Assay System ◽  
Beta Subunit ◽  
The Other ◽  
Alpha Subunit ◽  
Human Choriogonadotropin ◽  
Beta Hcg

Abstract We evaluated the Stratus (American Dade, Miami, FL), an automated immunofluorometric assay system, for the quantification of human choriogonadotropin (hCG) in serum or plasma. The assay is based on the "sandwich" (two-site) immunoassay methodology: use of two monoclonal antibodies, one specific for the alpha subunit and the other for the beta subunit, results in an assay that is specific for the intact hCG molecule. Results for the first sample are obtained in 7 min; subsequent additional values are produced at 1-min intervals. Inter-run precision (CV), estimated from replicate determinations of sera, was 4.5% at an hCG concentration of 38 int. units/L, 4.9% at 114, and 6.1% at 194. Intrarun CV was less than 2% at all three concentrations. Correlations of results for 127 specimens analyzed in duplicate with the Stratus (y) and by a radioimmunoassay (x) for beta hCG (Gamma Dab M [cf931125I] beta-hCG, Travenol-Genentech Diagnostics, Cambridge, MA) yielded the following regression equation: y = 0.969x - 6.0 (r = 0.995). The Stratus immunofluorometric system provides a rapid and convenient assay of hCG in serum or plasma.

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