scholarly journals Aflatoxin Plate Kit

2011 ◽  
Vol 94 (5) ◽  
pp. 1519-1530
Author(s):  
Arthur Trombley ◽  
Titan Fan ◽  
Robert LaBudde
Keyword(s):  
Immunosorbent Assay ◽  
Hplc Method ◽  
Aflatoxin Contamination ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rapid Testing ◽  
Total Aflatoxin ◽  
Standard Curve ◽  
Independent Laboratory ◽  
Test Kit

Abstract The level of total aflatoxin contamination was analyzed in naturally contaminated and spiked samples of corn and peanut using the Aflatoxin Plate Kit. This kit is an enzyme-linked immunosorbent assay (ELISA) suitable for rapid testing of grains and peanuts. The assay was evaluated for ruggedness and linearity of the standard curve. The test kit results were then statistically evaluated for accuracy, precision, and correlation to a validated HPLC method (AOAC 994.08). The results were verified by an independent laboratory.

scholarly journals A Calibration Curve Implanted Enzyme-Linked Immunosorbent Assay for Simultaneously Quantitative Determination of Multiplex Mycotoxins in Cereal Samples, Soybean and Peanut

Toxins ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 718
Author(s):  
Yuxiang Wu ◽  
Jinzhi Yu ◽  
Feng Li ◽  
Jianlin Li ◽  
Zhiqiang Shen
Keyword(s):  
Quantitative Determination ◽  
Immunosorbent Assay ◽  
Aflatoxin B1 ◽  
Calibration Curve ◽  
Hplc Method ◽  
New Method ◽  
Enzyme Linked Immunosorbent Assay ◽  
Standard Curve ◽  
Cereal Samples

In this study, a rapid and sensitive immunoassay method has been established based on calibration curve implanted enzyme-linked immunosorbent assay (C-ELISA) for the simultaneously quantitative determination of aflatoxin B1, deoxynivalenol and zearalenone in cereal samples, soybean and peanut. The C-ELISA avoids using the standard substances during the detection. The principle of the C-ELISA is to implant the optimized standard curve data into the matched analysis software which can make data processing more convenient and faster. The implanted calibration curve software was programmed with C plus plus. In the new immunoassay system for aflatoxin B1, deoxynivalenol and zearalenone, their linear detection ranges were from 0.03~0.81, 1.00~27.00 and 5.00~135.00 ng/g, respectively. Recovery rates from spiked samples ranged from 85% to 110% with the intra-assay coefficients of variation under 5%. Compared with HPLC method, the new method showed consistence in all the observed contents of the three mycotoxins in real samples. The new method can rapidly and reliably high throughput simultaneously screen for multiplex mycotoxins.

scholarly journals Detection of Aflatoxin in Poultry Feed and Feed Materials through Immuno Based Assay from Different Poultry Farms and Feed Factories in Bangladesh

2019 ◽  
Vol 35 (1) ◽  
pp. 75-78 ◽  
Author(s):  
Mahbuba Akter Lubna ◽  
Mita Debnath ◽  
Farzana Hossaini
Keyword(s):  
Health Risk ◽  
Positive Result ◽  
Mean Value ◽  
Aflatoxin Contamination ◽  
Control Measures ◽  
Poultry Feed ◽  
Enzyme Linked Immunosorbent Assay ◽  
Total Aflatoxin ◽  
Poultry Farms ◽  
Aflatoxin Concentration

Current study investigated the occurrence of aflatoxin contamination in poultry feed and feed materials in different poultry farms and feed factories in Bangladesh. A total of 100 samples of finished feed and raw feed materials were collected and tested through direct competitive Enzyme-Linked Immunosorbent Assay (ELISA) for total aflatoxin detection. Overall, 97% samples (n=97/100) in our study, were found positive for aflatoxin contamination. Among finished feed categories, layer grower feed contained highest level of aflatoxin with a mean value of 21.64 ppb whereas layer feed was less susceptible for aflatoxin contamination (mean value 9.49 ppb). Between raw feed materials, maize samples were highly contaminated (n=15/15, 100%) with aflatoxin while 86.67% soybean samples showed positive result. Twenty one percent (21%) of the samples in our study contained aflatoxin concentration more than the acceptable limit employed by USFDA and many other countries which might pose severe health risk to poultry and human consumer. Proper surveillance and immediate control measures should be taken to ensure safe poultry feed and feed materials. Bangladesh J Microbiol, Volume 35 Number 1 June 2018, pp 75-78

Enzyme-Linked Immunosorbent Assay for Microcystins in Blue-Green Algal Blooms

1990 ◽  
Vol 73 (3) ◽  
pp. 451-456 ◽  
Author(s):  
Fun S Chu ◽  
Xuan Huang ◽  
R D Wei
Keyword(s):  
Liquid Chromatography ◽  
Immunosorbent Assay ◽  
Algal Blooms ◽  
Ammonium Bicarbonate ◽  
Enzyme Linked Immunosorbent Assay ◽  
Standard Curve ◽  
Green Algal ◽  
Recovery Study ◽  
Minimum Detection Level ◽  
Elisa Plate

Abstract A direct competitive enzyme-linked immunosorbent assay (ELISA) for the freshwater blue-green algal toxin mlcrocystln (MCYST) In algae and water was developed. The assay Involves coating antl-MCYST-variant leuclne-arglnine (LR) antibody to the ELISA plate and the use of MCYST-LRperoxidase as the enzyme marker. The linear portion of the standard curve for MCYST in phosphate buffer containing saline (PBS) was 0.5-10.0 ng/mL (25-500 pg/assay). The minimum detection level for MCYST-LR was 0.20 ng/mL (10 pg/assay). Contaminated water could be directly used In the ELISA. The overall analytical recoveries for MCYST-LR added to water at levels of 1-20 ng/mL was 83.4%. For analysis of cellular MCYST, the toxin was first extracted from the algae with 0.1M ammonium bicarbonate, diluted with PBS to less than 0.5 mg dried algae/mL (<5.0 mg wet welght/mL) and directly used in the ELISA. C-18 reverse-phase Sep-Pak cartridges effectively adsorbed MCYST from the toxln-containlng solutions. The toxin could be recovered from the cartridge by elutlng with 60% methanol. Using this approach, an algae extract that was relatively free of MCYST was prepared and was used in a recovery study. The overall analytical recovery of MCYST added to the algae extract In the range of 0.25-20 ppm was 83% with a coefficient of variation of 11.9%. The detection limit for MCYST In dried algae was about 0.25-0.5 pg/g (0.25-0.5 ppm) lyophlllzed algae sample. This method was applied for the analysis of several naturally occurring algal blooms. Limited samples were also analyzed for MYCST by liquid chromatography. ELISA data were in general agreement with those obtainedby liquid chromatography. MCYST concentrations from 0.006 to 2.9 fig/g (6 to 2900 ppb) and from 26 to 5200 /ig/g (26 ppm to 5200 ppm) were found In water and algae (dried weight), respectively

Determination of Total Aflatoxin Levels in Peanut Butter by Enzyme-Linked Immunosorbent Assay: Collaborative Study

1992 ◽  
Vol 75 (4) ◽  
pp. 693-697 ◽  
Author(s):  
Alan L Patey ◽  
Matthew Sharman ◽  
John Gilbert
Keyword(s):  
Immunosorbent Assay ◽  
Aflatoxin B1 ◽  
Peanut Butter ◽  
Collaborative Study ◽  
The United States ◽  
Enzyme Linked Immunosorbent Assay ◽  
Total Aflatoxin ◽  
Aflatoxin Level ◽  
Relative Standard

Abstract Laboratories in Australia, Japan, Spain, the United Kingdom, and the United States participated in a collaborative study to evaluate a commercial enzyme- linked immunosorbent assay for the determination of total aflatoxin. Collaborators were sent 10 randomly numbered samples (5 blind duplicates) of roasted peanut butter. Two pairs were "blank" peanut butters to which aflatoxin B1, B2, G1, and G2 standards had been added. The other 3 pairs of peanut butters were 1 low aflatoxin level sample and 2 naturally contaminated samples. The assay is based on indirect competition. Test samples containing (free) aflatoxin, added to aflatoxin-coated microwells, compete for specific monoclonal rat anti-aflatoxin. As the concentration of aflatoxin in the test samples increases, the amount of rat antiaflatoxin binding to the aflatoxin attached to the well decreases. After a wash step to remove unbound material, the amount of rat anti-aflatoxin bound to the well is determined by its reaction with peroxidase conjugated rabbit anti-rat globulin. Bound peroxidase activity is then determined by the addition of a substrate, whose color development is inversely proportional to the aflatoxin concentration and is measured by absorbance. Coefficients of variation (CV) for total aflatoxin concentrations, for mean levels of 9,30, and 89µg/kg, were between 28 and 37% for the low level and 2 naturally contaminated samples, which contained mainly aflatoxin B1. CVs for the spiked samples were lower (24-25%) for mean levels of 11 and 20 µg/kg; recoveries were 84 and 89%, respectively. Ranges for relative standard deviations for repeatabilty and reproducibility were 9-30% and 25-37%, respectively. The method has been adopted first action by AOAC International.

scholarly journals Single-Dilution Enzyme-Linked Immunosorbent Assay for Quantification of Antigen-Specific Salmonid Antibody

2000 ◽  
Vol 12 (3) ◽  
pp. 245-252 ◽  
Author(s):  
Stewart W. Alcorn ◽  
Ronald J. Pascho
Keyword(s):  
Immunosorbent Assay ◽  
Sockeye Salmon ◽  
High Titer ◽  
Repeated Measurements ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Activity ◽  
Standard Curve ◽  
Test Fish ◽  
The Mean ◽  
Antibody Levels

An enzyme-linked immunosorbent assay (ELISA) was developed on the basis of testing a single dilution of serum to quantify the level of antibody to the p57 protein of Renibacterium salmoninarum in sockeye salmon ( Oncorhynchus nerka). The levels of antibody were interpolated from a standard curve constructed by relating the optical densities (OD) produced by several dilutions of a high-titer rainbow trout ( O. mykiss) antiserum to the p57 protein. The ELISA OD values produced by as many as 36 test sera on each microplate were compared with the standard curve to calculate the antigen-specific antibody activity. Repeated measurements of 36 samples on 3 microplates on each of 6 assay dates indicated that the mean intraassay coefficient of variation (CV) was 6.68% (range, 0–23%) and the mean interassay CV was 8.29% (range, 4–16%). The antibody levels determined for the serum sample from 24 sockeye salmon vaccinated with a recombinant p57 protein generally were correlated with the levels determined by endpoint titration ( r2 = 0.936) and with results from another ELISA that was based on extrapolation of antibody levels from a standard curve ( r2 = 0.956). The single-dilution antibody ELISA described here increases the number of samples that can be tested on each microplate compared with immunoassays based on analysis of several dilutions of each test serum. It includes controls for interassay standardization and can be used to test fish weighing <3 g.

Enzyme-Linked Immunosorbent Assay of Total Aflatoxins B1, B2, and G1 in Corn: Follow-up Collaborative Study

1994 ◽  
Vol 77 (3) ◽  
pp. 655-658 ◽  
Author(s):  
Mary W Trucksess ◽  
Michael E Stack
Keyword(s):  
Immunosorbent Assay ◽  
Polyclonal Antibodies ◽  
Collaborative Study ◽  
Screening Method ◽  
Test Sample ◽  
Enzyme Linked Immunosorbent Assay ◽  
Test Device ◽  
Total Aflatoxin ◽  
Peroxidase Conjugate

Abstract A direct competitive enzyme-linked immunosorbent assay screening method for af latoxins at 20 ng/g in corn was studied by 15 collaborating laboratories. Test samples of corn were extracted by blending with methanol-water (8 + 2). The extracts were filtered and the filtrates were diluted with buffer to a final methanol concentration of &lt;30%. Each diluted filtrate was applied to a test device containing a filter with immobilized polyclonal antibodies specific to aflatoxins B1, B2, and G1. Aflatoxin Bi-peroxidase conjugate was added, the test device was washed with water, and a mixture of hydrogen peroxide and tetramethylbenzidine was added. A test sample was judged to contain ≥20 ng af latoxins/g when, after exactly 1 min, no color was observed on the filter; if a blue or gray color developed, the test sample was judged to contain &lt;20 ng aflatoxins/g. All laboratories correctly identified naturally contaminated corn test samples. Only one false positive was found for controls containing no aflatoxins. The correct responses for positive test samples spiked at levels of 10,20, and 30 ng aflatoxins/g (the ratio of B1:B2:G1 was 15:1:3) were 67,97, and 100%, respectively. This method was adopted first action by AOAC INTERNATIONAL as a change in method for 990.34 for screening for aflatoxins B1, B2, and G1 in corn at total aflatoxin concentrations of ≥20 ng/g.

Disparities in estimates of IgG bound to normal platelets

Blood ◽  
1986 ◽  
Vol 67 (1) ◽  
pp. 200-202 ◽  
Author(s):  
N Blumberg ◽  
D Masel ◽  
M Stoler
Keyword(s):  
Direct Measurement ◽  
Immunosorbent Assay ◽  
Competitive Binding ◽  
Enzyme Linked Immunosorbent Assay ◽  
Binding Assays ◽  
Competitive Assay ◽  
Standard Curve ◽  
Normal Platelet ◽  
Direct Binding ◽  
Competitive Binding Assays

Abstract Estimates of the number of IgG molecules bound to normal platelets have ranged from several hundred to several tens of thousands. The lower estimates were generated from direct binding assays and stoichiometric assumptions. The higher values derive from competitive binding assays, in which platelet-associated IgG (PAIgG) is calculated from a standard curve using soluble IgG standards. Using a kinetic-ELISA (enzyme-linked immunosorbent assay) antiglobulin assay, we measured normal platelet IgG to be 21,200 +/- 9,400 molecules per platelet when a competitive assay and soluble IgG standards were used. Direct measurement of bound antiglobulin by kinetic-ELISA and stoichiometric assumptions yielded a measurement of 259 +/- 117 IgG molecules per platelet. Soluble IgG and PAIgG are not comparable in their ability to bind anti-IgG. Disparities in estimates of normal PAIgG are probably due to methodological differences. The estimate most likely to be correct is several hundred IgG or less per normal platelet.

Development of an Indirect Competitive Enzyme-Linked Immunosorbent Assay Based on the Multiepitope Peptide for the Synchronous Detection of Staphylococcal Enterotoxin A and G Proteins in Milk

2015 ◽  
Vol 78 (2) ◽  
pp. 362-369 ◽  
Author(s):  
MINGYAN LIANG ◽  
TINGTING ZHANG ◽  
XUELAN LIU ◽  
YANAN FAN ◽  
SHENGLIN XIA ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
Food Poisoning ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Synchronous Detection ◽  
Standard Curve ◽  
Stability And Accuracy

Staphylococcal food poisoning (SFP), one of the most common foodborne diseases, results from ingestion of staphylococcal enterotoxins (SEs) in foods. In our previous studies, we found that SEA and SEG were two predominant SE proteins produced by milk-acquired S. aureus isolates. Here, a tandemly arranged multiepitope peptide (named SEAGepis) was designed with six linear B-cell epitopes derived from SEA or SEG and was heterologously expressed. The SEAGepis-specific antibody was prepared by immunizing rabbit with rSEAGepis. Then, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on rSEAGepis and the corresponding antibody was developed to simultaneously detect SEA and SEG. Under the optimized conditions, the ic-ELISA standard curve for rSEAGepis was constructed in the concentration range of 0.5 to 512 ng/ml, and the average coefficients of variation of intra-and interassay were 4.28 and 5.61% during six standard concentrations. The average half-maximal inhibitory concentration was 5.07 ng/ml, and the limit of detection at a signal-to-noise ratio of 3 was 0.52 ng/ml. The anti-rSEAGepis antibody displayed over 90% cross-reactivity with SEA and SEG but less than 0.5% cross-reactivity with other enterotoxins. Artificially contaminated milk with different concentrations of rSEAGepis, SEA, and SEG was detected by the established ic-ELISA; the recoveries of rSEAGepis, SEA, and SEG were 91.1 to 157.5%, 90.3 to 134.5%, and 89.1 to 117.5%, respectively, with a coefficient of variation below 12%. These results demonstrated that the newly established ic-ELISA possessed high sensitivity, specificity, stability, and accuracy and could potentially be a useful analytical method for synchronous detection of SEA and SEG in milk.

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