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1.
J AOAC Int ; 98(6): 1571-84, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26651570

RESUMO

The QuickTox Kit for QuickScan Aflatoxin FREE uses competitive lateral flow technology and a reader based system for quantitative determination of total aflatoxins in varied matrixes. Aqueous based extraction protocols are used for corn and wheat, reducing use of solvents. Fifty percent ethanol (Reagent Alcohol) extraction is used for oats, sorghum, and barley. Eighty percent ethanol (Reagent Alcohol) extraction is used for whole peanut, peanut seed, and peanut hull samples. Matrix specific assay procedures and calibration curves are used to enable analyses across multiple sample types. The performance of this assay was examined using naturally contaminated aflatoxin corn samples and spiked samples of barley, oats, sorghum, wheat, whole peanut, peanut seed, and peanut hull samples. All data were judged against previously established acceptance criteria. Performance was evaluated in linearity, selectivity, matrix, lot consistency, and robustness experiments in the sponsor's laboratory. Results produced in all studies except robustness were within acceptable ranges. Out of range robustness study results reflected simultaneous deviation in sample volume and assay development time compared to the standard assay procedures. Aflatoxin B1, B2, and G1 were detected with approximately equal sensitivity; sensitivity for G2 was 64% that of B1. The presence of other common mycotoxins did not interfere with the assay. Matrix studies in an independent laboratory examined corn and barley to challenge both aqueous and ethanol based extraction procedures. All data points in these studies fell within the ranges defined in the acceptance criteria. The assay exhibited a linear dose response over the range tested, 0-100 ppb, with R(2) values exceeding 0.93 and RSDr values for results ranging from 2.27 to 23.84%.


Assuntos
Aflatoxinas/análise , Contaminação de Alimentos/análise , Kit de Reagentes para Diagnóstico
2.
J AOAC Int ; 98(1): 85-93, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25857883

RESUMO

Lateral flow technology and a reader-based system are used for quantitative determination of deoxynivalenol (DON), also known as vomitoxin, residues in cereal grain commodities by the QuickTox Kit for QuickScan DON (Vomitoxin). The assay has been modified, and a study was conducted in support of a Performance Tested MethodSM (PTM) Modification. The modified assay employs identical biologic reagents as used previously (PTM No. 121202). Compared to the PTM certified product, the new assay uses modified device architecture. Multiple kits and catalog numbers were required in the original kit reflecting the necessity for matrix specific calibration curves affixed to assay strips. A single calibration curve and kit are utilized in the new product; extraction volumes used in sample preparation are varied to accommodate multiple sample types. Extracts are clarified by filtration or settling depending on the sample type. Filtration was used for matrixes examined in these studies. With the original product, the extract was mixed 1:1 with DB1 buffer followed by the addition of the strip which was developed for 10 min. The new product dilutes extracts five-fold offline in DB6 buffer; an aliquot of the dilution is moved to a reaction vial followed by strip development time for 3 min. The new assay performance was evaluated for linearity, robustness, selectivity (inclusivity), lot-to-lot consistency, and both internal and third party matrix studies. All DON positive samples yielded results within previously defined acceptable ranges with dose-dependent correlation values of R2 greater than 0.97 in linearity and internal and external matrix studies. Inclusivity data indicated detection of DON along with acetyl derivatives, glucoside-conjugate, and Nivalenol. Robustness studies showed within range results upon co-variation of multiple user interface parameters, and lot-to-lot consistency challenges demonstrated acceptable results across five manufactured lots.


Assuntos
Contaminação de Alimentos , Tricotecenos/química , Estabilidade de Medicamentos , Kit de Reagentes para Diagnóstico
3.
J AOAC Int ; 97(5): 1359-73, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25902985

RESUMO

The DNAble Salmonella detection assay utilizes single overnight culture enrichment, user-friendly sample preparation, and isothermal DNA amplification for Salmonella detection. This report describes studies performed in support of AOAC Research Institute Performance Tested Method(SM) certification of the DNAble assay. Selectivity (inclusivity and exclusivity) studies were performed in the sponsor's laboratory. DNAble detected 119 out of 120 Salmonella isolates, representing 100 Salmonella serovars, in the inclusivity study while none of the 35 diverse non-Salmonella strains (32 species) tested was detected in the exclusivity study. Consistency (lot-to-lot and stability), instrument variation, and robustness studies were also conducted by the sponsor. Statistically equivalent assay performance was observed in these studies demonstrating robust assay manufacture and performance despite variation of multiple parameters in these challenges. Matrix studies, performed in an independent laboratory, evaluated DNAble assay performance in dry pet food, on stainless steel surfaces, and poultry environmental drag swab samples. Two sample sizes (25 and 375 g) and two culture volumes (9:1 and 3:1, v/w) were evaluated in separate matrix studies for dry pet food to provide multiple certified testing options for assay users. DNAble assay performance for dry pet food and stainless steel was compared to the procedures described in the U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual, Chapter 5, Salmonella. Assay performance for drag swabs was compared to protocols dictated in the FDA Environmental Sampling and Detection of Salmonella in Poultry Houses guidelines. Matrix study results demonstrated statistically equivalent DNAble assay performance compared to these reference methods, ensuring that the DNAble assay provides results comparable to those of the reference methods.


Assuntos
Técnicas de Amplificação de Ácido Nucleico/métodos , Kit de Reagentes para Diagnóstico , Salmonella/isolamento & purificação , Ração Animal/microbiologia , Animais , Salmonella/genética , Aço Inoxidável
4.
J AOAC Int ; 96(5): 1006-16, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24282939

RESUMO

The QuickTox Kit for QuickScan DON (Vomitoxin) uses lateral flow technology and a reader-based system for the quantification of deoxynivalenol (DON, vomitoxin) residues in cereal grain commodities. The present work was performed to obtain AOAC Research Institute Performance Tested MethodsM certification for testing wheat, maize, wheat bran, wheat flour, and barley samples with DON contamination levels as high as 5 ppm. Assay performance was examined using naturally contaminated and spiked samples in internal and independent laboratory evaluations and was compared to previously established acceptance criteria. Performance was evaluated with direct regard to linearity, matrix, selectivity, robustness, and stability. All data points in all studies were within the ranges defined in the acceptance criteria. The assay exhibited a linear dose response over the range tested, 0-5.0 ppm, with R2 values exceeding 0.97. RSD of repeatability, or RSDr, values for results ranged from 3.12 to 16.01% across all tested commodities and levels. Assay results were not affected by the presence of other common mycotoxins: aflatoxin B1, fumonisin B1, ochratoxin A, or zearalenone. Selectivity for modified DON was examined, specifically 15-acetyl DON, 3-acetyl DON, DON-3-glucoside, and another tricothecene, nivalenol; all were detected. The assay produced acceptable results in robustness studies when assay timing, temperature, and volume were covaried. The QuickTox Kit for QuickScan DON (Vomitoxin) assay is a convenient and reliable method for determination of DON in grain commodities.


Assuntos
Kit de Reagentes para Diagnóstico , Tricotecenos/análise , Estabilidade de Medicamentos , Contaminação de Alimentos , Tricotecenos/química
5.
J AOAC Int ; 96(5): 1019-25, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24282941

RESUMO

Quantitative, reader-based lateral flow technology is utilized for determination of ochratoxin contamination levels in wheat by the QuickTox Kit for QuickScan Ochratoxin-A. Naturally contaminated wheat samples were used to challenge the assay in the range of 0-100 ppb in linearity, selectivity, robustness, and stability, and in internal and external matrix studies. Performance was judged against criteria established by the AOAC Research Institute Performance Tested Method program prior to beginning the validation studies. All data produced during this work conformed to the acceptance criteria. Linear dose responses with R2 exceeding 0.97 and RSDr values between 6.22 and 17.10% for positive samples were observed in linearity and internal and external matrix studies. Ochratoxin A (OTA) and ochratoxin B (OTB) were detected by the assay. Assay sensitivity towards OTB was approximately 50% relative to OTA detection. Other common mycotoxins did not affect assay results. Variations in assay timing, temperature, and sample volume encompassed in the robustness study did not yield results outside the acceptable range. Determination of ochratoxin in wheat is facilitated using the QuickTox Kit for QuickScan Ochratoxin-A kit.


Assuntos
Ocratoxinas/análise , Kit de Reagentes para Diagnóstico , Triticum/química , Estabilidade de Medicamentos , Contaminação de Alimentos , Ocratoxinas/química
6.
J AOAC Int ; 95(5): 1460-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23175981

RESUMO

The QuickTox Kit for QuickScan Aflatoxin uses lateral flow technology and a reader-based system for quantitative determination of total aflatoxins. The performance of this assay was examined using corn samples naturally contaminated with aflatoxins in internal and independent laboratory evaluations and was judged against previously established acceptance criteria. Performance was evaluated for linearity, selectivity, matrix, robustness, and stability experiments. All data points in these studies fell within the ranges defined in the acceptance criteria. The assay exhibits linear dose response over the range tested, 0-100 ppb, with R2 values exceeding 0.98. RSDr values for results ranged from 4.7 to 17.7% across all tested levels. The four major aflatoxin types in corn are detected in the assay, with highest sensitivity for the most prevalent type, B1. Assay results are unaffected by the presence of other common mycotoxins. Robustness studies co-varied assay timing (-20%, 60% compared to the standard assay), temperature (18-30 degrees C), and sample volume (+/- 20% compared to the standard assay). Judged against the acceptance criteria, results were unaffected by these changes. The QuickTox Kit for QuickScan Aflatoxin assay is a user-friendly and reliable method for determination of total aflatoxins.


Assuntos
Aflatoxinas/química , Técnicas de Química Analítica/instrumentação , Contaminação de Alimentos/análise , Técnicas de Química Analítica/métodos , Kit de Reagentes para Diagnóstico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
7.
J Clin Microbiol ; 43(5): 2399-406, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15872273

RESUMO

Barriers to effective diagnostic testing for human immunodeficiency virus type 1 (HIV-1) infection can be reduced with simple, reliable, and rapid detection methods. Our objective was to determine the accuracy, sensitivity, and specificity of a new rapid, lateral-flow immunochromatographic HIV-1 antibody detection device. Preclinical studies were performed using seroconversion, cross-reaction, and interference panels, archived clinical specimens, and fresh whole blood. In a multicenter, prospective clinical trial, a four-sample matrix of capillary (fingerstick) whole-blood specimens and venous whole blood, plasma, and serum was tested for HIV-1 antibodies with the Efoora HIV rapid test (Efoora Inc., Buffalo Grove, IL) and compared with an enzyme immunoassay (EIA) (Abbott Laboratories) licensed by the Food and Drug Administration. Western blot and nucleic acid test supplemental assays were employed to adjudicate discordant samples. Preclinical testing of seroconversion panels showed that antibodies were often detected earlier by the rapid test than by a reference EIA. No significant interference or cross-reactions were observed. Testing of 4,984 archived specimens yielded a sensitivity of 99.2% and a specificity of 99.7%. A prospective multicenter clinical study with 2,954 adult volunteers demonstrated sensitivity and specificity for the Efoora HIV rapid test of 99.8% (95% confidence interval [CI], 99.3 and 99.98%) and 99.0% (95% CI, 98.5 and 99.4%), respectively. Reactive rapid HIV-1 antibody detection was confirmed in 99.6% of those with a known HIV infection (n = 939), 5.2% of those in the high-risk group (n = 1,003), and 0.1% of those in the low-risk group (n = 1,012). For 21 (0.71%) patients, there was discordance between the results of the rapid test and the confirmatory EIA/Western blot tests. We conclude that the Efoora HIV rapid test is a simple, rapid assay for detection of HIV-1 antibodies, with high sensitivity and specificity compared to a standardized HIV-1 EIA.


Assuntos
Anticorpos Anti-HIV/sangue , HIV-1/imunologia , HIV-1/isolamento & purificação , Soropositividade para HIV/sangue , Soropositividade para HIV/diagnóstico , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Virologia/métodos
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