scholarly journals Evaluation of Extraction Buffers Using the Current Approach of Detecting Multiple Allergenic and Nonallergenic Proteins in Food

2004 ◽  
Vol 87 (6) ◽  
pp. 1458-1465 ◽  
Author(s):  
Carmen D Westphal ◽  
Marion R Pereira ◽  
Richard B Raybourne ◽  
Kristina M Williams
Keyword(s):  
Peanut Butter ◽  
Current Trend ◽  
Current Approach ◽  
Detection Methods ◽  
Food Allergens ◽  
Extraction Buffer ◽  
Sample Extraction ◽  
Working Together ◽  
Commercial Kits ◽  
Analytical Variation

Abstract The detection of food allergens has been a challenge because of the increasing need to ensure the absence of undeclared allergens in foods. The current trend in the detection of some food allergens, like peanuts, is based on the detection of multiple allergenic and nonallergenic proteins, and this is the approach that kit manufacturers have adopted. Because commercial kits differ in their ability to detect allergens, regulatory agencies, the food industry, and kit manufacturers are working together to standardize the detection methods. Three kits for the detection of peanuts have been evaluated for performance by the AOAC Research Institute. For this evaluation, a peanut butter suspension was used as a reference material. Several kit components contribute to between-kit analytical variation, even when the same sample is used. One component of commercial kits, which may be contributing to this variability, is the sample extraction buffer. In this study, differences in extractability of 3 allergenic foods were evaluated by using 4 different extraction buffers. The conclusion is that optimum allergen extractability was buffer-dependent, and no single buffer is appropriate for use as a universal extraction solution for all allergenic foods. Therefore, a thorough evaluation of sample preparation buffers needs to be performed for every individual allergenic food. In light of the results obtained, the current approach used for detection of peanut allergens based on the detection of multiple allergenic and nonallergenic proteins is being analyzed.

scholarly journals Biosensors for the Determination of SARS-CoV-2 Virus and Diagnosis of COVID-19 Infection

2022 ◽  
Vol 23 (2) ◽  
pp. 666
Author(s):  
Maryia Drobysh ◽  
Almira Ramanaviciene ◽  
Roman Viter ◽  
Chien-Fu Chen ◽  
Urte Samukaite-Bubniene ◽  
...  
Keyword(s):  
Current Trend ◽  
Analytical Signal ◽  
Diagnostic Methods ◽  
Detection Methods ◽  
Label Free ◽  
Free Mode ◽  
Rna Hybridisation ◽  
Antigen Antibody ◽  
Affinity Interaction

Monitoring and tracking infection is required in order to reduce the spread of the coronavirus disease 2019 (COVID-19), induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To achieve this goal, the development and deployment of quick, accurate, and sensitive diagnostic methods are necessary. The determination of the SARS-CoV-2 virus is performed by biosensing devices, which vary according to detection methods and the biomarkers which are inducing/providing an analytical signal. RNA hybridisation, antigen-antibody affinity interaction, and a variety of other biological reactions are commonly used to generate analytical signals that can be precisely detected using electrochemical, electrochemiluminescence, optical, and other methodologies and transducers. Electrochemical biosensors, in particular, correspond to the current trend of bioanalytical process acceleration and simplification. Immunosensors are based on the determination of antigen-antibody interaction, which on some occasions can be determined in a label-free mode with sufficient sensitivity.

scholarly journals EFFICIENT METHOD OF DNA ISOLATION FROM BULKING SAMPLES OF SEEDLINGS

2021 ◽  
Vol 2021 (3) ◽  
pp. 29-48
Author(s):  
Irina Klimenko ◽  
Alexey Antonov ◽  
Vladimir Dushkin ◽  
Anastasia Shamustakimova ◽  
Yulian Mavlyutov
Keyword(s):  
Dna Isolation ◽  
Low Cost ◽  
Leaf Tissue ◽  
Perennial Grasses ◽  
Genetic Studies ◽  
Modified Method ◽  
Extraction Buffer ◽  
Low Efficiency ◽  
Commercial Kits ◽  
The Individual

Forage annual and perennial grasses are the difficult subject for molecular and genetic studies because of the problem with obtaining qualitative genomic DNA for PCR, due of high content of proteins, polysaccharides and polyphenols. The known methods of DNA extraction or the numerous commercial kits allow isolating purified nucleic acids from the leaf tissue, but characterized by low efficiency at seedlings using. The modified method of DNA isolation, based on the SDS-extraction buffer (sodium dodecil sulfate), is presented in this study. Significant modifications were introduced in the reagents compound and the steps of procedure accordingly to used type of plant tissue and the result was positive at usage on the bulking samples, as well as on the individual genotypes (the only seedling). Reliability of this method and the functionality of the obtained DNA samples were tested in PCR with different molecular markers (SSR, SRAP and PawS) in researches on revealing of forage legume grasses DNA polymorphism. The general advantages of the proposed method are simplicity and effectiveness, the possibility to isolate qualitative DNA without toxic reagents application, as well as relatively low cost and availability of reagents. This method can be useful for studying the genetic biodiversity and for decision the different tasks, required the rapid analysis of large plant populations.

scholarly journals A supervised method for object-based 3D building change detection on aerial stereo images

2014 ◽  
Vol XL-3 ◽  
pp. 259-264 ◽  
Author(s):  
R. Qin ◽  
A. Gruen
Keyword(s):  
Change Detection ◽  
Current Trend ◽  
Detection Methods ◽  
Support Vector ◽  
Detection Accuracy ◽  
Status Change ◽  
Aerial Photos ◽  
Object Based ◽  
The Status

There is a great demand for studying the changes of buildings over time. The current trend for building change detection combines the orthophoto and DSM (Digital Surface Models). The pixel-based change detection methods are very sensitive to the quality of the images and DSMs, while the object-based methods are more robust towards these problems. In this paper, we propose a supervised method for building change detection. After a segment-based SVM (Support Vector Machine) classification with features extracted from the orthophoto and DSM, we focus on the detection of the building changes of different periods by measuring their height and texture differences, as well as their shapes. A decision tree analysis is used to assess the probability of change for each building segment and the traffic lighting system is used to indicate the status "change", "non-change" and "uncertain change" for building segments. The proposed method is applied to scanned aerial photos of the city of Zurich in 2002 and 2007, and the results have demonstrated that our method is able to achieve high detection accuracy.

scholarly journals SARS-CoV-2 RNA extraction using magnetic beads for rapid large-scale testing by RT-qPCR and RT-LAMP

2020 ◽  
Author(s):  
Steffen Klein ◽  
Thorsten G. Mueller ◽  
Dina Khalid ◽  
Vera Sonntag-Buck ◽  
Anke-Mareil Heuser ◽  
...  
Keyword(s):  
Large Scale ◽  
Magnetic Beads ◽  
Rna Extraction ◽  
Magnetic Bead ◽  
Viral Rna ◽  
Detection Sensitivity ◽  
Detection Methods ◽  
Extraction Protocol ◽  
Large Scale Testing ◽  
Commercial Kits

Rapid large-scale testing is essential for controlling the ongoing pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The standard diagnostic pipeline for testing SARS-CoV-2 presence in patients with an ongoing infection is predominantly based on pharyngeal swabs, from which the viral RNA is extracted using commercial kits followed by reverse transcription and quantitative PCR detection. As a result of the large demand for testing, commercial RNA extraction kits may be limited and alternative, non-commercial protocols are needed. Here, we provide a magnetic bead RNA extraction protocol that is predominantly based on in-house made reagents and is performed in 96-well plates supporting large-scale testing. Magnetic bead RNA extraction was benchmarked against the commercial QIAcube extraction platform. Comparable viral RNA detection sensitivity and specificity were obtained by fluorescent and colorimetric RT-LAMP using N primers, as well as RT-qPCR using E gene primers showing that the here presented RNA extraction protocol can be combined with a variety of detection methods at high throughput. Importantly, the presented diagnostic workflow can be quickly set up in a laboratory without access to an automated pipetting robot.

Application of Multiantigen Profiling To Detect Pecan

2018 ◽  
Vol 81 (5) ◽  
pp. 700-704 ◽  
Author(s):  
CHUNG Y. CHO ◽  
CAROLINE PUENTE-LELIEVRE ◽  
GRANT D. JONES ◽  
SARAH R. STADIG ◽  
DEBRA A. TAYLOR ◽  
...  
Keyword(s):  
Dna Analysis ◽  
Current Trend ◽  
Diverse Group ◽  
Food Allergens ◽  
Analytical Challenge ◽  
Primary Methods ◽  
Tree Nuts ◽  
Detection And Identification ◽  
Detection Assay ◽  
Allergen Detection

ABSTRACTA problem often encountered in the detection and identification of undeclared tree nut food allergens is the lack of analytical methods. This problem is accentuated by the current trend, whereby the primary methods used to detect food allergens are antibody-based enzyme-linked immunosorbent assays (ELISAs) and the development of analyte-specific antibodies takes months. The recently developed xMAP food allergen detection assay (xMAP FADA) has the ability to generate multiantigen profiles with tree nuts, thereby providing a potential solution to this problem. The xMAP FADA includes 22 antibodies targeting peanut, soy, and nine tree nuts. The high number of antibodies to a diverse group of tree nuts and legumes and the propensity of tree nuts to cross-react have enabled the development of multiantigen profiling, whereby an analyte reacts with the various antibodies to generate a profile. Recently, a question arose regarding the possible presence of pecan dust at a manufacturer of pecan products that also stored fresh produce. The lack of suitable pecan ELISAs created an analytical challenge that was resolved using multiantigen profiling with the xMAP FADA. Pecan was detected on swab samples by using multiantigen profiling and confirmed by DNA analysis. The use of multiantigen profiling provided an analytical capability beyond what was possible with an analyte-specific analytical method.

A House in the Woods by I. Moore

2012 ◽  
Vol 2 (2) ◽  
Author(s):  
Sandy Campbell
Keyword(s):  
Nuclear Family ◽  
Peanut Butter ◽  
Health Sciences ◽  
University Of Alberta ◽  
Construction Methods ◽  
Record Player ◽  
Working Together ◽  
Sharing Space ◽  
The University

Moore, Inga. A House in the Woods. Somerville, MA: Candlewick Press, 2011.  Print. A House in the Woods is all about getting along, working together and sharing space. The story centres around a version of a nuclear family, in this case a male moose, a female bear and two little pigs.  Initially the pigs each have homes, but bear and moose each take over one of the pigs’ homes and are too big so they accidentally destroy them.  Then they all decide together to have the beavers build a house for them.  These, however, are not ordinary beavers.  They drive trucks and are paid in peanut butter sandwiches. The beavers gnaw the trees down and then everyone works to build the house. In the end the moose, bear and little pigs move in and live happily in their snug house. English author/illustrator Inga Moore has created an idyllic forest world in which all of the anthropomorphized animals cooperate. The animals walk on their hind legs, sit on benches , buy things at the store, wash dishes and sleep in beds.  Moore has drawn an odd combination of construction methods. On one page, the animals are shown raising frame walls with ropes and on the facing page, the building has notched log construction with walls built from the ground up.  Apart from that inconsistency, the images are lovely.  Many of them have details which will amuse children.  For example, during the construction, one of the pigs delivers tea on a trolley to the workers.  In the picture of the trucks arriving with furniture, there are lots of objects to find:  a trumpet, a record player, a meat grinder, a penny-farthing and several rather startled-looking squirrels.   In the store a tiny mouse with a blue and white apron sweeps the counter.  The house has a distinctly English cottage look to it with a steeply pitched roof and external stone fireplaces.  Set in the dark autumn-coloured forest, it looks like it might have been a witch’s house, but we know better, so it looks cosy and comfortable. Overall, the book has an idyllic and comforting look and feel that sets a nice tone for a bed-time read.  This book is recommended for public, school and home libraries. Highly recommended: 4 out of 4 stars Reviewer: Sandy CampbellSandy is a Health Sciences Librarian at the University of Alberta, who has written hundreds of book reviews across many disciplines.  Sandy thinks that sharing books with children is one of the greatest gifts anyone can give.

Robustness Testing of the xMAP Food Allergen Detection Assay: A Multiplex Assay for the Simultaneous Detection of Food Allergens

2020 ◽  
Vol 83 (6) ◽  
pp. 1050-1056 ◽  
Author(s):  
PRASAD RALLABHANDI ◽  
CHUNG Y. CHO ◽  
WILLIAM L. NOWATZKE ◽  
KERRY G. OLIVER ◽  
ERIC A. E. GARBER
Keyword(s):  
Food Allergen ◽  
Incubation Temperature ◽  
Simultaneous Detection ◽  
Multiplex Assay ◽  
Food Allergens ◽  
Assay Procedure ◽  
Extraction Buffer ◽  
Detection Assay ◽  
Assay Performance ◽  
Allergen Detection

ABSTRACT The xMAP food allergen detection assay (xMAP FADA) can simultaneously detect 15 analytes (14 food allergens plus gluten) in one analysis. The xMAP FADA typically employs two antibody bead sets per analyte, providing built-in confirmation that is not available with other antibody-based assays. Before an analytical method can be used, its reliability must be assessed when conditions of the assay procedure are altered. This study was conducted to determine the effects on assay performance associated with changes in incubation temperature, amounts of the antibody bead cocktail, and concentrations of detection antibody and β-mercaptoethanol in the reduced-denatured extraction buffer. The analysis of buffered-detergent extracts revealed lower responses at 22°C than at 37°C, but temperature had no effect on the analysis of reduced-denatured extracts. Changes in β-mercaptoethanol and detection antibody concentrations had an effect on the detection of only milk in the reduced-denatured extracts. A slight change in the measured bead count was observed when one-fourth of the bead cocktail was used, and a large decrease in the bead count was noted when one-eighth of the recommended amount was used, but this number (≥25) was still sufficient to provide reliable results. Overall, the xMAP FADA was very robust to changes in the assay procedure, which may inadvertently occur. HIGHLIGHTS

scholarly journals Reliability of real-time RT-PCR tests to detect SARS-Cov-2: A literature review

2020 ◽  
Vol 11 ◽  
pp. 13 ◽  
Author(s):  
Clément Bezier ◽  
Géraldine Anthoine ◽  
Abdérafi Charki
Keyword(s):  
Real Time ◽  
World Health ◽  
Detection Methods ◽  
Rt Pcr ◽  
Health Crisis ◽  
The Face ◽  
Commercial Kits ◽  
Health Organization ◽  
Technical Capacity ◽  
The Impact

In the face of the COVID-19 (Coronavirus Disease 2019) pandemic, the World Health Organization (WHO) has urged countries to test the population more widely. Clinical laboratories have been confronted with a huge demand for testing and have had to make urgent preparations for staff training, to establish new analytical processes, reorganize the workspace, and stock up on specific equipment and diagnostic test kits. The reliability of SARS-Cov-2 test results is of critical importance, given the impact it has on patient care and the management of the health crisis. A review of the literature available for the period leading up to and including June 2020 on the reliability of SARS-Cov-2 (Severe Acute Respiratory Syndrome Coronavirus) detection methods using real-time RT PCR (Reverse Transcription - Polymerase Chain Reaction) brings together the primary factors teams of scientists claim or demonstrate to affect the reliability of results. A description is given of the RT-PCR testing method, followed by a presentation of the characteristics and validation techniques used. A summary of data from the literature on the reliability of tests and commercial kits for SARS-Cov-2 detection, including current uncertainties with regard to the molecular targets selected and genetic diversity of SARS-Cov-2 is provided. The limitations and perspectives are then discussed in detail in the light of the bibliographic data available. Many questions have been asked that still remain unanswered. The lack of knowledge about this novel virus, which appeared at the end of 2019, has a significant impact on the technical capacity to develop reliable, rapid and practical tools for its detection.

scholarly journals LAMP Assay for the Detection of Echinococcus multilocularis Eggs Isolated from Canine Faeces by a Cost-Effective NaOH-Based DNA Extraction Method

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 847
Author(s):  
Barbara J. Bucher ◽  
Gillian Muchaamba ◽  
Tim Kamber ◽  
Philipp A. Kronenberg ◽  
Kubanychbek K. Abdykerimov ◽  
...  
Keyword(s):  
Multiplex Pcr ◽  
Dna Extraction ◽  
Sensitivity And Specificity ◽  
Echinococcus Multilocularis ◽  
Lamp Assay ◽  
High Sensitivity ◽  
Cost Effective ◽  
Detection Methods ◽  
Simple Method ◽  
Commercial Kits

The detection of Echinococcus multilocularis in infected canids and the environment is pivotal for a better understanding of the epidemiology of alveolar echinococcosis in endemic areas. Necropsy/sedimentation and counting technique remain the gold standard for the detection of canid infection. PCR-based detection methods have shown high sensitivity and specificity, but they have been hardly used in large scale prevalence studies. Loop-mediated isothermal amplification (LAMP) is a fast and simple method to detect DNA with a high sensitivity and specificity, having the potential for field-application. A specific LAMP assay for the detection of E. multilocularis was developed targeting the mitochondrial nad1 gene. A crucial step for amplification-based detection methods is DNA extraction, usually achieved utilising silica-gel membrane spin columns from commercial kits which are expensive. We propose two cost-effective and straightforward methods for DNA extraction, using NaOH (method 1A) and InstaGeneTM Matrix (method 1B), from isolated eggs circumventing the need for commercial kits. The sensitivity of both assays with fox samples was similar (72.7%) with multiplex-PCR using protocol 1A and LAMP using protocol 1B. Sensitivity increased up to 100% when testing faeces from 12 foxes infected with more than 100 intestinal stages of E. multilocularis. For dogs, sensitivity was similar (95.4%) for LAMP and multiplex-PCR using protocol 1B and for both methods when DNA was extracted using protocol 1A (90.9%). The DNA extraction methods used here are fast, cheap, and do not require a DNA purification step, making them suitable for field studies in low-income countries for the prevalence study of E. multilocularis.

scholarly journals MÉTODO OPTIMIZADO PARA LA EXTRACCIÓN DE DNA DE Sargassum liebmannii

e-CUCBA ◽  
2021 ◽  
Vol 8 (16) ◽  
pp. 45-49
Author(s):  
Hwan Woo Jung Kim ◽  
◽  
Paulina Velasco-Ramírez ◽  
Rosalba Mireya Hernández-Herrera ◽  
Ildefonso Enciso-Padilla ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Secondary Metabolites ◽  
Molecular Marker ◽  
Deoxyribonucleic Acid ◽  
Extraction Methods ◽  
Chain Reaction ◽  
Extraction Buffer ◽  
Polymerase Chain ◽  
High Concentrations ◽  
Commercial Kits

Macroalgae contains high concentrations of polysaccharides, polyphenols and secondary metabolites. Those compounds are factors that prevent the isolation of deoxyribonucleic acid (DNA) and therefore inhibit the polymerase chain reaction (PCR) that is the beginning for the application of any molecular marker. In the present study, the application of six extraction methods was documented; four of them conventional and two commercial kits. The highest efficiency in DNA extraction was obtained with a conventional method with modifications. Said modifications consisted of immersing the algal tissue in ß-mercantoethanol and the addition of the DIECA salt in the extraction buffer. To test the purity of the DNA, in addition to the electrophoresis and spectrophotometry methods, a PCR was performed for the ISSR molecular marker, obtaining amplified fragments using the aforementioned modification.

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