scholarly journals Determination of Egg Proteins in Food Products by Enzyme Immunoassay

2000 ◽  
Vol 83 (1) ◽  
pp. 139-143 ◽  
Author(s):  
Jupiter M Yeung ◽  
W Harvey Newsome ◽  
Michael A Abbott
Keyword(s):  
Detection Limit ◽  
Enzyme Immunoassay ◽  
Polyclonal Antibodies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antigen Binding ◽  
Food Ingredients ◽  
Coefficients Of Variation ◽  
Egg Products ◽  
Whole Egg

Abstract An enzyme-linked immunosorbent assay (ELISA) was developed to determine the presence of egg proteins in foods. The polyclonal antibodies developed were specific to whole egg proteins and did not cross-react with any of the 38 nuts, legumes, or other common food ingredients tested. The concentrations of egg proteins that will inhibit 50% of antibody–antigen binding, IC50, were 3–7 ng/mL, and the linear range was 0.5–62.5 ng/mL. The detection limit was 0.2 ppm for various foods. Recoveries ranged from 67 to 96%. The intra- and inter-assay coefficients of variation in this procedure were 10–13% for ice cream spiked at 0.8 and 1.6 ppm. The ELISA has been applied to ice creams, noodles, pasta, and breads. Egg proteins were identified in all declared egg products, and no false positives were found.

Development of Enzyme Immunoassay for Captan and Its Degradation Product Tetrahydrophthalimide in Foods

1993 ◽  
Vol 76 (2) ◽  
pp. 381-386 ◽  
Author(s):  
W Harvey Newsome ◽  
Jupiter M Yeung ◽  
Peter G Collins
Keyword(s):  
Detection Limit ◽  
Human Serum Albumin ◽  
Degradation Product ◽  
Protein Concentration ◽  
Polyclonal Antibodies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Test Compound ◽  
Coefficients Of Variation ◽  
Spacer Arm ◽  
Related Compounds

Abstract A simple, sensitive, and precise enzyme-linked immunosorbent assay (ELISA) is described for the quantitation of captan as its degradation product tetrahydrophthalimide (THPI) in foods using polyclonal antibodies. Three hapten analogues of THPI with different alky I spacer arm lengths were synthesized. Immunogens and coating proteins were prepared by coupling these haptens to human serum albumin and ovalbumin, respectively. A 5-carbon spacer arm appeared to be optimum for the production of antibodies. Heterologous coating proteins did not improve the sensitivity, but reduction of homologous coating protein concentration did improve the sensitivity, resulting in a concentration of test compound required to inhibit binding by 50% of 15.5 ng/mL The antiserum is specific for captan, captafol, and THPI, but not other structurally related compounds. The minimum detection limit was 1 ng/mL; the linearity was 1-200 ng/mL. The overall recoveries of captan and THPI from 11 commodities spiked at 4 levels were 92 and 100%, respectively. The intra-assay and interassay coefficients of variation were 9.1 and 16.8% for apple blanks and 5.9 and 4.2% for apple spiked with 3 ppm THPI, respectively. The ELISA described is suitable for measuring captan and THPI at levels comparable to those typically found in fruit.

scholarly journals Determination of Citrinin in Barley by Indirect and Direct Enzyme Immunoassay

1996 ◽  
Vol 79 (6) ◽  
pp. 1325-1329 ◽  
Author(s):  
David Abramson ◽  
Ewald Usleber ◽  
Erwin Martlbauer
Keyword(s):  
Enzyme Immunoassay ◽  
Solid Phase ◽  
Polyclonal Antibodies ◽  
Detection Limits ◽  
Keyhole Limpet Hemocyanin ◽  
Buffer Solutions ◽  
Microtiter Plates ◽  
Coefficients Of Variation ◽  
Optimum Extraction

Abstract Polyclonal antibodies against the mycotoxin citrinin were raised in rabbits after immunization with citrinin conjugated to keyhole limpet hemocyanin. The antibodies were used in a competitive indirect enzyme immunoassay (EIA) with citrinin coupled to glucose oxidase as the solid-phase antigen for coating microtiter plates. Detection limits of this indirect EIA for citrinin ranged from 0.4 to 0.8 ng/mL for buffer solutions. Recoveries of citrinin added to ground barley at 100–2000 ng/g ranged from 105 to 112%, with coefficients of variation between 4.5 and 12%. A direct competitive EIA also was established, with citrinin coupled to horseradish peroxidase as the labeled antigen. Detection limits of this direct EIA for citrinin ranged from 2 to 4 ng/mL for buffer solutions. Recoveries of citrinin added to ground barley at 500–2000 ng/g ranged from 108 to 111%, with coefficients of variation between 8.4 and 26.9%. In naturally contaminated barley samples assayed with the indirect EIA, optimum extraction of citrinin was obtained in 30 min, and only one extraction was necessary to recover 72–76% of the analyte.

Development of an Analytical Protocol for the Determination of Polybrominated Biphenyls in Water by Enzyme-Linked Immunosorbent Assay

2011 ◽  
Vol 347-353 ◽  
pp. 1537-1541 ◽  
Author(s):  
Han Yu Chen ◽  
Hui Sheng Zhuang
Keyword(s):  
Detection Limit ◽  
Quantitative Determination ◽  
Incubation Time ◽  
Polyclonal Antibodies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Concentration ◽  
Polybrominated Biphenyls ◽  
Analytical Protocol ◽  
Optimized Conditions

A novel immunoassay has been developed for the quantitative determination of polybrominated biphenyls (PBBs) using indirect competitive format. A new method was developed to synthesize PBBs congener (PCB15) hapten and its artificial immunogen, then the polyclonal antibodies. The assay was optimized concerning the coating conjugate and antibody concentration, incubation time and temperature, the tolerance to organic solvents and so on. Under optimized conditions, PBB15 can be determined in the concentration range of 0.01-100 μg L-1 with a detection limit of 0.02 μg L-1. The cross-reactivities of the assays were below 8%. While water samples could be analyzed directly.

Production of Antibodies and Development of Enzyme Immunoassay for Determination of Monensin in Biological Samples

1987 ◽  
Vol 70 (2) ◽  
pp. 201-205
Author(s):  
Michael E Mount ◽  
Douglas L Failla
Keyword(s):  
Enzyme Immunoassay ◽  
Immunosorbent Assay ◽  
Biological Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Coefficients Of Variation ◽  
Highly Sensitive

Abstract Monensin is converted to monensin bromoacetate, which provides successful coupling to protein and allows production of monensinspeciflc rabbit antisera. A modified indirect enzyme-linked immunosorbent assay (ELISA) was developed, which is highly sensitive (2 ng/mL) to monensin determination. Monensin recovery was 53- 81% at 10 ppb in sera or urine, and 81-130% at 100 ppb in dichloromethane- extracted feces or water. Overall recovery was 98.8% with coefficients of variation from 6 to 52% over the range of monensin concentrations studied. This is the first immunoassay reported for the carboxylic ionophore antibiotics.

Determination of Ochratoxin A in Feed by Immunoaffinity Cleanup and Liquid Chromatography

2013 ◽  
Vol 96 (3) ◽  
pp. 599-602 ◽  
Author(s):  
Ping Ding ◽  
Ziyou Mi ◽  
Yali Hou ◽  
Yigang He ◽  
Jianhua Xie
Keyword(s):  
Liquid Chromatography ◽  
Detection Limit ◽  
Ochratoxin A ◽  
Cyanogen Bromide ◽  
Polyclonal Antibodies ◽  
Immunoaffinity Column ◽  
Low Levels ◽  
Sepharose 4B ◽  
Feed Samples

Abstract A method using LC was developed for determination of ochratoxin A (OTA) in feeds. The extracted samples were cleaned up by an immunoaffinity column prepared by covalently coupling polyclonal antibodies against OTA to cyanogen bromide-activated Sepharose 4B. The eluates were determined by LC with fluorescence detection. Recoveries of OTA from fortified samples of 1–10 μg/kg levels ranged from 84.3 to 90.0%, with CVs of 3.3–7.8%. The detection limit was 0.045 μg/kg based on an S/N of 3:1. A total of 65 feed samples were screened for OTA with the proposed method. The results showed that only nine samples were contaminated with OTAs at low levels. The presented method was successfully applied to quantify OTAs in real feed samples.

Direct solid-phase enzymoimmunoassay of testosterone in saliva.

1989 ◽  
Vol 35 (10) ◽  
pp. 2044-2047 ◽  
Author(s):  
K Howard ◽  
M Kane ◽  
A Madden ◽  
J P Gosling ◽  
P F Fottrell
Keyword(s):  
Detection Limit ◽  
Analytical Procedure ◽  
Solid Phase ◽  
Medical Applications ◽  
Microtiter Plates ◽  
Large Numbers ◽  
Coefficients Of Variation ◽  
Serial Sampling ◽  
Direct Solid

Abstract This competitive, solid-phase enzymoimmunoassay for testosterone in saliva is carried out on microtiter plates and involves no chromatographic or extraction steps. With an overnight incubation the detection limit of the assay is 230 fg per well (16.1 pmol/L). There was a good correlation (correlation coefficient 0.95) between testosterone concentrations measured with and without prior extraction of the saliva samples. Repeated assay of three control saliva samples containing a range of testosterone concentrations (200-1000 pmol/L) gave within- and between-assay coefficients of variation of 5.5-13.2%. The analytical procedure is simple and closely resembles already published procedures for the determination of progesterone and estrone (with extraction) in saliva. One person can assay 200 samples in 24 h and the assay is suitable for reproductive and sports medical applications, particularly for projects involving serial sampling and yielding large numbers of samples.

scholarly journals Characterization and validation of fragment antigen-binding (Fab) antibody-based immunoassay for deoxymiroestrol, a potent phytoestrogen from Pueraria candollei

2021 ◽  
Author(s):  
Worapol Sae-foo ◽  
Supaluk Krittanai ◽  
Wipawee Juengsanguanpornsuk ◽  
Gorawit Yusakul ◽  
Tharita Kitisripanya ◽  
...  
Keyword(s):  
Quantitative Method ◽  
Estrogenic Activity ◽  
Limit Of Detection ◽  
Hormone Replacement ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antigen Binding ◽  
Pueraria Candollei ◽  
Specific Determination ◽  
Fragment Antigen Binding

Deoxymiroestrol is the most potent phytoestrogen in chromenes group that has been found in Pueraria candollei, Thai name known as Kwao Krua Khao. Several studies reported estrogenic activity of P. candollei in order to using as hormone replacement therapy for postmenopausal women. Previously, specific determination of deoxymiroestrol content by enzyme-linked immunosorbent assay (ELISA) using polyclonal antibody (pAb) have been reported. However, production of pAb has limitation and variability from different batches. Therefore, in this study, we established quantitative method for determination of deoxymiroestrol using fragment antigen-binding (Fab) antibody-based immunoassay. The developed immunoassay has specificity to deoxymiroestrol with a calibration range of 15.6-1000 ng mL-1. Precision including intra-assay and inter-assay are 1.48-7.11 and 0.58-9.31%, respectively. Accuracy of the assay showed in recovery between 99.77-101.61% when spike deoxymiroestrol standard into the samples. The limit of detection (LOD) is 30.80 ng mL-1. Comparation antibody-based immunoassay for determination of deoxymiroestrol using Fab with pAb was represented consistency (R2 = 0.9807) when analysis roots bark of Pueraria candollei from difference areas. Therefore, this development assay can apply to determine deoxymiroestrol content in the plant samples.

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.

Determination of Methyl 2-Benzimidazolecarbamate in Wine by Competitive Inhibition Enzyme Immunoassay

1993 ◽  
Vol 76 (4) ◽  
pp. 851-856 ◽  
Author(s):  
Rodney J Bushway ◽  
Lance R Paradis ◽  
Lewis B Perkins ◽  
Titan S Fan ◽  
Barbara E S Young ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Competitive Inhibition ◽  
White Wines ◽  
Average Recovery ◽  
Total Analysis Time ◽  
Coefficients Of Variation ◽  
Limit Of Quantitation ◽  
Total Analysis ◽  
Commercial Kit

Abstract A benomyl polyclonal enzyme immunoassay (EIA) commercial kit was used to quantitate methyl 2- benzimidazolecarbamate (MBC), a degradation product of benomyl in wine. Total analysis time, including sample preparation, was 30 min. As many as 8 samples can be analyzed simultaneously with a limit of quantitation of 5 ppb. The assay logarithmic response was linear from 0.4 to 26 ppb MBC. Intra-assay percent coefficients of variation (%CVs) ranged from 2.4 to 13 for standards and from 7.4 to 21 for actual wine samples. Interassay %CVs varied from 2.6 to 15 for the standards and from 6.9 to 23 for the samples. Average recovery from samples spiked at 10–10 000 ppb was 93% for evaporated red and white wines. MBC was determined in 134 different wines by immunoassay and liquid chromatography (LC). Of these samples, 98 were positive for MBC by both methods with a correlation coefficient (r) of 0.986. The other 36 samples had MBC levels that either were not detectable by either procedure or were below the 10 ppb limit of quantitation for LC. Concentrations of MBC in wine ranged from 5 to 1329 ppb, with the majority ranging from 10 to 300 ppb. Also, a mini-study was conducted using the plate EIA format.

Sandwich enzyme immunoassay of Mucor miehei proteinase (Fromase) in cheese

1989 ◽  
Vol 56 (5) ◽  
pp. 793-797 ◽  
Author(s):  
Pavel Rauch ◽  
Igor Hochel ◽  
Eva Beránková ◽  
Jan Káš
Keyword(s):  
Detection Limit ◽  
Horseradish Peroxidase ◽  
Enzyme Immunoassay ◽  
Commercial Preparation ◽  
Mucor Miehei ◽  
Cross Reactions ◽  
Sandwich Enzyme Immunoassay

SummarySandwich enzyme immunoassay of Mucor miehei proteinase (from the commercial preparation Fromase) has been developed using horseradish peroxidase as a marker. The enzyme may be determined to a detection limit of 50 ng/ml. Slight cross reactions by chymosin, bovine, porcine and chicken pepsin did not affect the assay. Recovery of Fromase added to cheese extracts varied between 92 and 106%. The method was used for the determination of M. miehei proteinase in different cheese extracts.

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