Search results for "ELISA"
showing 10 items of 169 documents
Una lectura de 'La honestidad defendida de Elisa Dido, reina y fundadora de Cartago' de A. Cubillo de Aragón.
2007
La honestidad defendida de Elisa Dido es la única comedia con tema mitológico escrita por Álvaro Cubillo de Aragón. La estructura de la pieza revela la gran habilidad del escritor para construir el argumento, y también los diferentes tonos que predominan en cada una de las tres partes o jornadas que la integran. En general, los personajes están bien delineados, siendo de especial interés la Reina Dido y Tabanco, el gracioso. En lo concerniente a Dido, no muestra la frialdad y la incompatibilidad con la comedia de intriga que le ha atribuido la crítica; por lo que se refiere a Tabanco, es mucho más que el simple tipo de gracioso. Estas consideraciones junto con el final inesperado con el que…
Immunoanalytical approaches for the control of xenobiotics and biotoxins in food
2020
[ES] El control efectivo de la calidad y seguridad de los alimentos requiere de métodos analíticos que garanticen la determinación fiable de cualquier sustancia potencialmente perjudicial para el consumidor que pueda estar presente en el alimento antes de su distribución y comercialización. Una de las aproximaciones analíticas que contribuye a garantizar este objetivo engloba una serie de técnicas que tienen en común la utilización de anticuerpos como elementos esenciales para la detección del analito diana, y que en conjunto reciben el nombre de métodos inmunoquímicos. Este artículo pretender aportar una visión básica de los principios bioquímicos subyacentes a estas tecnologías y cuáles…
Site-heterologous haptens and competitive monoclonal antibody-based immunoassays for pyrimethanil residue analysis in foodstuffs
2015
Pyrimethanil is a widely used post-harvest fungicide whose residues are commonly found in fruits and vegetables. We herein report the synthesis of two new functionalized derivatives of pyrimethanil carrying an equivalent spacer arm at different positions of the molecule. The influence of the linker tethering site on the affinity of monoclonal antibodies was shown. Moreover, the development of competitive immunoassays in different formats and with high sensitivity to the target analyte - IC50 values below 0.3μg/L - is described. Optimized assays were characterized by the determination of the limit of quantification, trueness, and precision using water-diluted QuEChERS extracts of fruits and …
Analysis of Chlorpyrifos in Water, Fruit Juice, and Honeybee Extract by Chemiluminescent Elisa
2008
Abstract The suitability of competitive enzyme-linked immunosorbent assays (ELISAs) with chemiluminescent detection-based immobilized antigen (indirect assay) for rapid and accurate determination of chlorpyrifos in various food matrices was tested. The limit of detection (LOD) values were 1–1.75 ng mL−1, the standard curve midpoint (IC50) was 3.5 ng mL−1, and the assay duration was 1.5 h. Assay application to the analysis of honeybee extract resulted in chlorpyrifos recoveries varying between 62 and 83% in 5–15 ng mL−1 herbicide concentration range.
Quantification of Imidacloprid in Honeybees: Development of a Chemiluminescent ELISA
2010
A Chemiluminescente Enzyme-Linked Immuno-Sorbent Assay (CL-ELISA) for determination and quantification of the fungicide imidacloprid in honeybees was developed in an indirect competitive format. The assay was optimized by determining: the optimal coating conjugate concentration and anti-imidacloprid antiserum dilution, the effect of the incubation time on the competitive step, the tolerance to organic solvents. The IC50 and the limit of detection (LOD) values were 14.8 ng mL-1 and 0.11 ng mL -1, respectively, similar to those of colorimetric ELISA with a calibration range of 0.1 – 2600 ng mL-1. Cross reactivity of some related compounds such as three imidacloprid metabolites, 6-chloro nicot…
Development of monoclonal antibody-based competitive immunoassays for the detection of picoxystrobin in cereal and oilseed flours
2012
Picoxystrobin is a new generation fungicide primarily developed to be used in cereal crops. In the present study a novel collection of specific monoclonal antibodies has been produced using different immunizing haptens based on a carboxy-functionalized identical spacer arm attached to alternative positions of the target pesticide molecule. Two competitive enzyme-linked immunosorbent assays have been developed employing hapten heterology, one using the antibody-coated direct format and the other in the conjugate-coated indirect format. Both immunoassays have been characterized in terms of selectivity, solvent tolerance, and buffer conditions, affording similar limits of detection at or below…
Moiety and linker site heterologies for highly sensitive immunoanalysis of cyprodinil in fermented alcoholic drinks
2015
Cyprodinil is a new-generation anilinopyrimidine fungicide widely used in crop protection and frequently found in fruits. In this study, novel derivatives of cyprodinil with linker site heterologies were synthesized and employed in order to produce antibodies with enhanced affinity. Moreover, moiety-heterologous haptens were designed and prepared for assay sensitivity improvement. Two competitive enzyme-linked immunosorbent assays for the analysis of this active substance were developed using direct and indirect formats, achieving IC50 values around 0.15 μg/L. Analytical figures of merit and usability of the optimized assays were evaluated with wine and cider as model food processed matrice…
Development of a sensitive and specific enzyme-linked immunosorbent assay for the determination of fludioxonil residues in fruit juices
2014
Fludioxonil is a fungicide with a singular mode of action that is widely employed in the treatment of fruit crops. A competitive enzyme-linked immunosorbent assay (cELISA) has been developed and validated for the determination of residues of this fungicide in fruit juices. A collection of monoclonal antibodies (mAbs) against the fungicide fludioxonil has been produced and characterized using direct and indirect cELISAs. The high affinity achieved (IC50lower than 0.5 μg L-1) considerably improved that obtained with previous polyclonal antibodies. The proposed cELISA was applied to the analysis of fludioxonil residues in apple juice and red grape must samples with a limit of quantification of…
Brief an Garlieb H. Merkel
1798
Ms. 930a, Nr. 12, Bl. 31r-34v Johannes Daniel Falk. Brief an Garlieb H. Merkel, Weimar, den 3. December 179[8?] Autora rokraksts / Autograph, vācu val. / Deutsch [8] lpp. / S. Attēlu numuri / Bildnummern: 930a-012-1, 930a-012-2-3, 930a-012-4-5, 930a-012-6-7, 930a-012-8 Im vorliegenden Brief vermischen sich private und berufliche Angelegenheiten sowie Klatsch miteinander. Nachdem Falk seine lange Antwortzeit zunächst damit begründet, dass er Merkels aktuelle Adresse nicht kenne, bringt er Neuigkeiten von der Krankheit einer nicht näher benannten Kammerrätin und nimmt an deren Leiden rege Anteil. Direkt im Anschluss präsentiert Falk den Stand seiner Verhandlungen mit Verlegern. Auch wenn Falk…
Determination of trace levels of organic fining agents in wines: Latest and relevant findings
2022
The production of red wine plays a key role in the local and international economies of several nations. During the winemaking process, to clarify the final product, before bottling, and to remove undesired substances (proteins, phenols, and tannins), fining agents are commonly added to wines. These substances have different origins (animal and vegetable proteins or mineral compounds), and they show a potential risk for the health of allergic subjects. For these reasons, the residues of fining agents, constituted by exogenous proteins based on gluten, egg, and milk proteins, should not be present in the final product and their trace residues should be quantified with accuracy. In the last d…