scholarly journals Unreliable Measurement of Basophil Maximum Leukotriene Release with the Bühlmann CAST 2000 Enzyme-Linked Immunosorbent Assay Kit

2006 ◽  
Vol 13 (3) ◽  
pp. 420-422 ◽  
Author(s):  
S. E. Burastero ◽  
C. Paolucci ◽  
D. Breda ◽  
G. Monasterolo ◽  
R. E. Rossi ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Immunosorbent Assay ◽  
False Positive ◽  
Positive Control ◽  
Enzyme Linked Immunosorbent Assay ◽  
Positive Results

ABSTRACT The Bühlmann CAST 2000 enzyme-linked immunosorbent assay is a potentially useful assay for measuring sulfidoleukotrienes released in vitro by allergen-challenged basophils. However, we observed that the positive-control reagent yielded positive signals in cell-free systems. These false-positive results depended on using a mouse anti-FcεRI monoclonal antibody and were prevented by degranulation-inducing reagents other than mouse monoclonal antibodies.

scholarly journals Detection of False-Positive Sera in Contagious Agalactia with a Multiantigen ELISA and their Elimination with a Protein G Conjugate

1998 ◽  
Vol 10 (4) ◽  
pp. 326-330 ◽  
Author(s):  
Maurice Lambert ◽  
Michel Calamel ◽  
Philippe Dufour ◽  
Evelyne Cabasse ◽  
Christian Vitu ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Immunosorbent Assay ◽  
False Positive ◽  
Enzyme Linked Immunosorbent Assay ◽  
Protein G ◽  
Mycoplasma Agalactiae ◽  
Cross Reactions ◽  
Serologic Diagnosis ◽  
Contagious Agalactia ◽  
The Past

In serology, lack of specificity can generally be attributed to cross-reactions between different pathogens with antigens bearing similar epitopes. During seroepidemiologic surveys of contagious agalactia of sheep caused by Mycoplasma agalactiae infection, numerous sera were analyzed by enzyme-linked immunosorbent assay (ELISA). A few sera reacted with various antigens coated on plates, including the well with no antigen. This reactivity was not due to cross-reactions as initially suspected, and these multipositive sera were designated false-positive sera. Elimination of this false positivity was not possible by using covalent ELISA plates or different rabbit anti-sheep IgG conjugates. Only conjugates using monoclonal antibodies or protein G were efficient in elimination of false positivities without reducing the true specific positive titers. No false-positive sera have been observed since the implementation of protein G conjugates in the serologic diagnosis of contagious agalactia by ELISA for the past 2 years.

Sensitive Measurement of Thrombopoietin by a Monoclonal Antibody Based Sandwich Enzyme-linked Immunosorbent Assay

1997 ◽  
Vol 78 (04) ◽  
pp. 1262-1267 ◽  
Author(s):  
Claudia C Folman ◽  
Albert E G K von dem Borne ◽  
Irma H J A M Rensink ◽  
Winald Gerritsen ◽  
C Ellen van der Schoot ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Immunosorbent Assay ◽  
Platelet Transfusion ◽  
Large Scale ◽  
Limit Of Detection ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Reliable Tool

SummaryIn this report a sensitive enzyme-linked immunosorbent assay (ELISA) for the measurement of plasma thrombopoietin (Tpo) is described that is solely based on monoclonal antibodies (MoAbs).The assay has an intra and inter-assay variance of 5-7% and 7-13%, respectively. Native and recombinant human Tpo (rhTpo) were recognized equally well, no cross reactivity with other cytokines was found and rhTpo added to plasma and serum was completely recovered. With the ELISA, Tpo concentrations in EDTA-anticoagulated plasma of all controls (n = 193) could be determined, since the limit of detection (2 ± 0.8 A.U./ml, mean ± sd) was lower than the concentration found in controls (11 ± 8 A.U./ml, mean ± sd; 2.5th-97.5th percentile: 4-32 A.U./ml). Tpo levels in serum were on average 3.4 times higher than in plasma.We showed in vivo that Tpo is bound by platelets, as in thrombocytopenic patients (n = 5) a platelet transfusion immediately led to a drop in plasma Tpo level, whereas in patients receiving chemotherapy the induced thrombocytopenia was followed by a rise in plasma Tpo levels.In summary, these results indicate that this ELISA is a reliable tool for Tpo measurements and is applicable for large scale studies.

False-positive galactomannan antigen testing in pulmonary nocardiosis

2020 ◽  
Author(s):  
Arnon Haran ◽  
Violeta Temper ◽  
Marc Assous ◽  
Michael Bergel ◽  
Noga Chahanian ◽  
...  
Keyword(s):  
At Risk ◽  
Early Diagnosis ◽  
False Positive ◽  
Clinical Sample ◽  
Lavage Fluid ◽  
Enzyme Linked Immunosorbent Assay ◽  
Pulmonary Nocardiosis ◽  
First Time ◽  
Positive Results

Abstract Early diagnosis of invasive aspergillosis (IA) is facilitated by detection of galactomannan (GM) in serum and bronchoalveolar lavage fluid (BALF) using an enzyme-linked immunosorbent assay (ELISA). Although accurate, false positive results have been reported with these tests in numerous contexts. We report for the first time the occurrence of false positive GM ELISA due to nocardiosis, initially in a clinical sample of BALF from a patient with pulmonary nocardiosis, and subsequently corroborated by in vitro reactivity of 26% of tested isolates. Since patients at risk for IA are also at risk for nocardiosis, this finding has important clinical implications. Lay Summary Early diagnosis of aspergillosis has been facilitated by the routine use of antibody-based detection of galactomannan in various bodily fluids. We report for the first time the occurrence of false positive results of this assay in the context of nocardiosis.

scholarly journals Simple Histidine-Rich Protein 2 Double-Site Sandwich Enzyme-Linked Immunosorbent Assay for Use in Malaria Drug Sensitivity Testing

2005 ◽  
Vol 49 (8) ◽  
pp. 3575-3577 ◽  
Author(s):  
Harald Noedl ◽  
Jan Bronnert ◽  
Kritsanai Yingyuen ◽  
Bernhard Attlmayr ◽  
Herwig Kollaritsch ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Monoclonal Antibodies ◽  
Immunosorbent Assay ◽  
Drug Sensitivity ◽  
Inhibitory Concentration ◽  
Enzyme Linked Immunosorbent Assay ◽  
Sensitivity Testing ◽  
Drug Sensitivity Test ◽  
Sensitivity Tests

ABSTRACT A simple double-site sandwich enzyme-linked immunosorbent assay (ELISA) for Plasmodium falciparum in vitro drug sensitivity tests based on measuring histidine-rich protein 2 (HRP2) is presented. The ELISA uses two commercial monoclonal antibodies and provides a drastically cheaper alternative to the test kits previously used in the HRP2 drug sensitivity test. The assay is simple to establish and perform. The sensitivity is comparable and the drug sensitivity results very closely match those obtained with the commercial ELISA kits (R 2 = 0.979; P < 0.001; mean log difference at the 50% inhibitory concentration = 0.07).

scholarly journals Characterization of a monoclonal antibody that probes the functional domains of the glucocorticoid receptor

1987 ◽  
Vol 246 (1) ◽  
pp. 55-65 ◽  
Author(s):  
N M Robertson ◽  
W F Kusmik ◽  
B F Grove ◽  
A Miller-Diener ◽  
M L Webb ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Glucocorticoid Receptor ◽  
Glucocorticoid Receptors ◽  
Enzyme Linked Immunosorbent Assay ◽  
Functional Domain ◽  
Cytoplasmic Staining ◽  
Receptor Complexes ◽  
Specificity And Sensitivity

Monoclonal antibodies to the rat hepatic glucocorticoid receptor (GR) were produced by using 4000-fold-purified unactivated rat hepatic GR as the immunogen in an immunization in vitro. Hybridomas were screened for anti-GR antibody production by using an enzyme-linked immunosorbent assay. The antibody, 3A6, described here, is an IgM (lambda). The interaction of 3A6 with the purified GR was explored by sedimentation analysis, where a shift of the 9 S GR to a form with a higher s20,w value was demonstrated. Binding specificity and sensitivity were demonstrated by protein immunoblotting. 3A6 cross-reacted with all rat tissue glucocorticoid receptors (GRs) examined, except those of the brain. Species cross-reactivity was observed with other mammalian GRs (from human CEM-C7 cells and from pig and mouse liver). Immunocytochemical localization of the GR was assessed by indirect immunofluorescence in intact fixed cells, which demonstrated intense cytoplasmic staining in the absence of pretreatment with glucocorticoids and nuclear localization when cells were pretreated with glucocorticoids. This monoclonal antibody significantly inhibited steroid binding to unoccupied receptor and DNA binding of activated steroid-receptor complexes. Furthermore, preincubation of the purified activated GR complex with 3A6 prevented phosphorylation of the GR in vitro. Thus 3A6 differs from previous monoclonal antibodies to the GR in its capacity to cross-react with the human GR and by its specificity for an epitope on or near a functional domain of the GR.

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