Enzyme immunoassay for factor VIII-related antigen.

Abstract I describe a simple enzyme-linked immunosorbent assay (ELISA) for the quantitation of Factor VIII-related antigen in plasma with use of commercially available peroxidase-labeled antiserum and solid-phase support. Regression analysis of 85 plasma samples analyzed by this technique (y) and by a commonly used electroimmunoassay (Anal. Biochem. 15: 45-52, 1966) (x) gave the equation y = 0.223 + 0.77x (r = 0.973). The present method was also compared with enzyme immunoassay in which a phosphatase-labeled antiserum prepared in our laboratory was used; the correlation between the two assays was very good. The simplicity and specificity of the ELISA technique should make it a useful alternative to the more difficult and time-consuming Laurell method.

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Evaluation of Solid-Phase Chemiluminescent Enzyme Immunoassay, Enzyme-Linked Immunosorbent Assay, and Latex Agglutination Tests for Screening Toxoplasma IgG in Samples Obtained from Cats and Pigs

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063870001200206 ◽

2000 ◽

Vol 12 (2) ◽

pp. 136-141 ◽

Cited By ~ 5

Author(s):

Ashok K. Singh

Keyword(s):

Enzyme Immunoassay ◽

Immunosorbent Assay ◽

Solid Phase ◽

Latex Agglutination ◽

Clinical Samples ◽

Enzyme Linked Immunosorbent Assay ◽

Elisa Method ◽

Serum Samples ◽

Positive Results ◽

Chemiluminescent Enzyme Immunoassay

Serum samples from cats and pigs were analyzed by the solid-phase chemiluminescent enzyme immunoassay (SPCEI), enzyme-linked immunosorbent assay (ELISA), and indirect latex agglutination (ILA) methods. The SPCEI and ILA methods accurately analyzed Toxoplasma IgG (T-IgG) in both clinical and spiked samples from pigs and cats. The ELISA method accurately analyzed T-IgG in spiked samples from cats and pigs or clinical samples from pigs, but it did not accurately analyze T-IgG in clinical samples from cats. The antibody used in the ELISA kit did not cross-react with cat T-IgG. The SPCEI method that uses a stand-alone automated analyzer provided quantitative analysis, whereas the ELISA and ILA methods provided qualitative or, at best, semiquantitative analysis of T-IgG. The SPCEI and ELISA methods were rapid (60–90 minutes for 30 samples), whereas the ILA method required 13–15 hours for 30 samples. Although the three methods accurately distinguished positive from negative samples, the ILA method yielded many weakly positive results that were not confirmed by either the ELISA or SPCEI method. Thus, the indirect agglutination tests may give nonspecific responses at lower T-IgG concentrations.

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Evaluation of Three Commercial Serological Tests with Different Methodologies To Assess Helicobacter pyloriInfection

Journal of Clinical Microbiology ◽

10.1128/jcm.37.12.4150-4152.1999 ◽

1999 ◽

Vol 37 (12) ◽

pp. 4150-4152 ◽

Cited By ~ 19

Author(s):

A. van der Ende ◽

R. W. M. van der Hulst ◽

P. Roorda ◽

G. N. J. Tytgat ◽

J. Dankert

Keyword(s):

Helicobacter Pylori ◽

Enzyme Immunoassay ◽

Immunosorbent Assay ◽

Solid Phase ◽

Enzyme Linked Immunosorbent Assay ◽

Serological Tests ◽

H Pylori ◽

Chemiluminescent Enzyme Immunoassay

The sera of 142 Helicobacter pylori-positive and 32H. pylori-negative patients were assessed by a desktop test (QuickVue), an enzyme-linked immunosorbent assay (ELISA) (HM-CAP), and a solid-phase, two-step chemiluminescent enzyme immunoassay (Immulite). These tests yielded sensitivities of 97, 97, and 91% and specificities of 97, 94, and 100%, respectively. In conclusion, the desktop test and the ELISA are more sensitive than the chemiluminescent enzyme immunoassay (P < 0.05). The chemiluminescent enzyme immunoassay has the advantage that it is fully automated.

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Detection of the carrier state for classic hemophilia using an enzyme- linked immunosorbent assay (ELISA)

Blood ◽

10.1182/blood.v59.6.1163.1163 ◽

1982 ◽

Vol 59 (6) ◽

pp. 1163-1168 ◽

Cited By ~ 11

Author(s):

DJ Fishman ◽

PK Jones ◽

JE Menitove ◽

OD Ratnoff ◽

B Everson

Keyword(s):

Discriminant Analysis ◽

Factor Viii ◽

Immunosorbent Assay ◽

Quantitative Estimate ◽

Carrier State ◽

Enzyme Linked Immunosorbent Assay ◽

Heterologous Antiserum ◽

Elisa Technique ◽

Normal Women ◽

Antihemophilic Factor

Abstract A high proportion of carriers of classic hemophilia can be identified in the laboratory because, in comparison to normal women, the concentration of antigens related to antihemophilic factor (AHF, factor VIII) that are detected in their plasma by heterologous antiserum (factor VIIIR:Ag) is relatively higher than the titer of AHF that is measured in clotting assays (factor VIII:C). Enzyme-linked immunosorbent assay (ELISA) appears to overcome some of the technical difficulties associated with measurement of AHF-like antigens. The results of ELISA correlated closely with those obtained by semiquantitative immunoelectrophoresis, except in patients with von Willebrand's disease. In which ELISA appeared to provide a more quantitative estimate of AHF-like antigen. Utilizing the ELISA technique and a revised method of logarithmic discriminant analysis, we were able to distinguish all of 37 obligate carriers of hemophilia at the level of certainty that would have misclassified 5% of normal women as carriers. The relative simplicity of ELISA suggests its utility in the diagnosis of the carrier state in the female relatives of hemophiliacs.

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Use of monoclonal antibodies in an enzyme immunoassay for factor VIII-related antigen.

Clinical Chemistry ◽

10.1093/clinchem/30.1.87 ◽

1984 ◽

Vol 30 (1) ◽

pp. 87-92 ◽

Cited By ~ 9

Author(s):

L A Bradley ◽

E L Franco ◽

H M Reisner

Keyword(s):

Monoclonal Antibodies ◽

Factor Viii ◽

Solid Phase ◽

Mammalian Species ◽

Test Sample ◽

Inhibitory Effect ◽

Enzyme Linked Immunosorbent Assay ◽

Response Curves ◽

Factor Viii Related Antigen ◽

Assay Precision

Abstract Two monoclonal antibodies (MAb 53, MAb D7) were produced, each having specificity for Factor VIII-related antigen (FVIIIR:Ag), but exhibiting no inhibitory effect on either procoagulant activity or the ability of von Willebrand factor to agglutinate platelets in the presence of the antibiotic ristocetin. For quantification of FVIIIR:Ag, we used the antibodies in a competitive enzyme-linked immunosorbent assay (ELISA). Binding of either of the MAb's to solid-phase antigen was inhibited by free FVIIIR:Ag in the test sample. Dose-response curves for the reference standards were consistently linear (r2 greater than 0.990) and reproducible. The normal range of FVIIIR:Ag detected in plasma (normal defined as 1000 units/L) was similar to that reported for polyclonal heterologous antibodies in similar ELISA or immunoradiometric (IRMA) systems, and the assay was sensitive to 10 units of FVIIIR:Ag per liter. Inter- and intra-assay precision was good, coefficients of variation being less than 11%. Studies on patients showed good correlations between values measured by MAb ELISAS and IRMA (polyclonal rabbit antibody) over FVIIIR:Ag concentrations ranging from less than 10 to 2700 units/L (r = 0.971, p less than 0.001 for MAb 53; r = 0.938, p less than 0.001 for MAb D7). Both ELISAS could be used to quantify FVIIIR:Ag in other mammalian species. The assay is inexpensive and simple, and all reagents required for it are commercially available.

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Detection of the carrier state for classic hemophilia using an enzyme- linked immunosorbent assay (ELISA)

Blood ◽

10.1182/blood.v59.6.1163.bloodjournal5961163 ◽

1982 ◽

Vol 59 (6) ◽

pp. 1163-1168

Author(s):

DJ Fishman ◽

PK Jones ◽

JE Menitove ◽

OD Ratnoff ◽

B Everson

Keyword(s):

Discriminant Analysis ◽

Factor Viii ◽

Immunosorbent Assay ◽

Quantitative Estimate ◽

Carrier State ◽

Enzyme Linked Immunosorbent Assay ◽

Heterologous Antiserum ◽

Elisa Technique ◽

Normal Women ◽

Antihemophilic Factor

A high proportion of carriers of classic hemophilia can be identified in the laboratory because, in comparison to normal women, the concentration of antigens related to antihemophilic factor (AHF, factor VIII) that are detected in their plasma by heterologous antiserum (factor VIIIR:Ag) is relatively higher than the titer of AHF that is measured in clotting assays (factor VIII:C). Enzyme-linked immunosorbent assay (ELISA) appears to overcome some of the technical difficulties associated with measurement of AHF-like antigens. The results of ELISA correlated closely with those obtained by semiquantitative immunoelectrophoresis, except in patients with von Willebrand's disease. In which ELISA appeared to provide a more quantitative estimate of AHF-like antigen. Utilizing the ELISA technique and a revised method of logarithmic discriminant analysis, we were able to distinguish all of 37 obligate carriers of hemophilia at the level of certainty that would have misclassified 5% of normal women as carriers. The relative simplicity of ELISA suggests its utility in the diagnosis of the carrier state in the female relatives of hemophiliacs.

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Enzyme Linked Immunosorbent Assay (ELISA)

Natural Sciences Engineering and Technology Journal ◽

10.37275/nasetjournal.v1i2.6 ◽

2021 ◽

Vol 1 (2) ◽

pp. 29-38

Author(s):

Maya Chandra Dita

Keyword(s):

Quality Control ◽

Enzyme Immunoassay ◽

Immunosorbent Assay ◽

Solid Phase ◽

Control Measures ◽

Diagnostic Tools ◽

Enzyme Linked Immunosorbent Assay ◽

Antigen Binding ◽

Fluorogenic Substrate ◽

Specific Antibodies

Enzyme immunoassay (EIA) and enzyme-linked immunosorbent assay (ELISA) are both widely used as diagnostic tools in medicine and as quality control measures in many industries. ELISA has been the system of choice when testing soluble antigens and antibodies. EIA / ELISA uses the basic immunological concept of antigen binding to specific antibodies, which allows the detection of small amounts of antigens such as proteins, peptides, hormones or antibodies in fluid samples. In all protocols, solid-phase reagents are incubated with secondary or tertiary reactants covalently coupled with the enzyme. The unbound conjugate is washed and a chromogenic or fluorogenic substrate is added.

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Factor VIII : C and Factor VIII R: Ag in Argentine Hemorrhagic Fever

Thrombosis and Haemostasis ◽

10.1055/s-0038-1653402 ◽

1981 ◽

Vol 46 (02) ◽

pp. 525-527 ◽

Cited By ~ 10

Author(s):

Felisa C Molinas ◽

Julio I Maiztegui

Keyword(s):

Factor Viii ◽

Normal Values ◽

Hemorrhagic Fever ◽

Plasma Samples ◽

Two Dimensional ◽

Plasma Infusion ◽

Factor Viii Related Antigen ◽

Clinical Forms ◽

Argentine Hemorrhagic Fever ◽

Immune Precipitation

SummaryFactor VIII procoagulant activity (F VIII: C) and factor VIII related antigen (F VIII R: Ag) were investigated in 35 patients with Argentine hemorrhagic fever. Since the results obtained in the three clinical forms of the disease were not significantly different, they were tabulated altogether. F VIII: C was low in early stages of the disease but increased progressively in later days (days 5–6:0.54 ± 0.10 I.U./ml; days 13–14:0.95 ± 0.13 I.U./ml). In contrst, the levels of F VIII R: Ag were high all along the disease and they returned to normal values during the convalescence period (days 5–6; 2.58 ± 0.54 I.U./ml; day 30: 1.30 ± 0.14 I.U./ml). The levels of F VIII R: Ag were similar in samples drawn before (11 cases) or after (10 cases) the treatment with immune plasma infusion. Plasma samples from 12 patients were studied by two-dimensional immunelectrophoresis. The only abnormality found was increased height of the immune precipitation arc.

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A Simple Enzyme-Immunoassay (EIA) Test for Factor VIII-Related Antigen (VIIIAGN)

Thrombosis and Haemostasis ◽

10.1055/s-0038-1666933 ◽

1979 ◽

Vol 42 (03) ◽

pp. 848-854 ◽

Cited By ~ 22

Author(s):

Paul M Ness ◽

Herbert A Perkins

Keyword(s):

Factor Viii ◽

Enzyme Immunoassay ◽

Hemophilia A ◽

Single Sample ◽

Healthy Controls ◽

Von Willebrand's Disease ◽

Factor Viii Related Antigen ◽

Von Willebrand’S Disease ◽

Increased Sensitivity

SummaryAn enzyme immunoassay (EIA) system has been developed to measure factor VIII- related antigen (VIIIAGN). This assay gives similar results to the commonly used Laurell electroimmunodiffusion (EID) assay for VIIIAGN as shown by comparison of both techniques with samples from healthy controls, patients with hemophilia A, and patients with von Willebrand’s disease. The assay also has a greater precision than the EID technique as demonstrated by multiple assays of aliquots of a single sample. The use of this EIA test for VIIIAGN is simple and employs inexpensive reagents and equipment. The use of expensive antisera is minimized. EIA for VIIIAGN has the advantage of increased sensitivity compared to Laurell EIA.

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