scholarly journals Overview of Portable Assays for the Detection of Mycotoxins, Allergens, and Sanitation Monitoring

2020 ◽  
Author(s):  
Ronald W Sarver ◽  
David J Almy ◽  
Eric R Bergeron ◽  
Benjamin F Strong ◽  
Brent A Steiner ◽  
...  
Keyword(s):  
Disodium Salt ◽  
Distillers Grains ◽  
Diagnostic Assay ◽  
Salt Hydrate ◽  
Protein Assay ◽  
Diagnostic Assays ◽  
Diagnostic Kits ◽  
Environmental Surfaces ◽  
Food Recalls ◽  
Sources Of Contamination

Abstract Background Many food recalls are related to the presence of undeclared allergens and microorganisms in food products. To reduce these occurrences, portable diagnostic assay kits are available to quantitate mycotoxins, to detect allergens and gluten in foods and on environmental surfaces, and for sanitation monitoring. Objective This article reviews diagnostic kits that can detect sources of contamination in food and ingredients as well as on surfaces and clean-in-place rinses. Method Mycotoxins and gluten were detected using lateral flow diagnostic assays. Sanitation monitoring of surfaces was completed using a chemiluminescent assay to detect adenosine 5′-triphosphate disodium salt hydrate (ATP) and another assay to detect protein. Results Gluten was detected at 10 ppm in spiked commodities and on wet and dry surfaces at 2.5 µg/100cm2. Deoxynivalenol was quantitated in dry distillers grains plus solubles and mean results were within two SDs of those determined by HPLC. The chemiluminescent assay had an LOD of 6 fmol of ATP and was able to detect a 1:10 000 dilution of orange juice from surfaces. The protein assay detected 5 µg of bovine serum albumin (BSA) directly applied to the sampler, 100 µg of BSA on surfaces, and detected 1:10 dilutions of Greek yogurt and raw beef from surfaces. Conclusions Portable diagnostic kits evaluated in this work provided accurate, rapid, and sensitive results for detection of mycotoxins, gluten, proteins, and ATP. These methods can be used in facilities with minimal training and provide results that are important to ensure food safety. Highlights Portable methods to detect gluten, mycotoxins, proteins, and ATP are presented.

The dynamicity of light-up aptamers in one-pot in vitro diagnostic assays

The Analyst ◽  
2022 ◽  
Author(s):  
Marimuthu Citartan
Keyword(s):  
Diagnostic Assay ◽  
One Pot ◽  
Direct Modulation ◽  
Diagnostic Assays ◽  
In Vitro Diagnostic ◽  
Targeted Detection

The direct modulation of a light-up aptamer that engenders an analyte-specific aptamer-light-up aptamer chimera is readily applicable in any diagnostic assay for a targeted detection.

scholarly journals The reactivation of reprogramming factors within human blastocysts by using ATP contribute to human blastocyst development

2017 ◽  
Author(s):  
Takashi Takemura ◽  
Midori Okabe
Keyword(s):  
Transcription Factor ◽  
Disodium Salt ◽  
The Other ◽  
Blastocyst Development ◽  
Salt Hydrate ◽  
Pou Domain ◽  
Human Blastocyst ◽  
Mouse Hepatocytes ◽  
Reprogramming Factors ◽  
Transcription Factor 1

AbstractScientists worldwide have been unable to replicate the stimulus-triggered acquisition of pluripotency (STAP) cells and/or the STAP phenomenon. However, investigations into STAP cells and/or the STAP phenomenon by RIKEN CDB in Japan found that ATP (adenosine 5’-triphosphate disodium salt hydrate) can upregulate Oct3/4 (POU5F1: POU domain, class 5, transcription factor 1) and Nanog mRNA expression in mouse hepatocytes.On the other hand, no studies have investigated whether ATP can contribute to human blastocyst development. Here we show the reactivation of reprogramming factors within human blastocysts by appropriate ATP treatment (1 mM for 2 days) can contribute to human blastocyst development.In conclusion, although ATP treatment could not replicate STAP cells and/or the STAP phenomenon by scientists worldwide, appropriate ATP treatment (1 mM for 2 days) in cultured human blastocysts with totipotency would be helpful for infertility women.

scholarly journals A Fluorescence Kinetic-Based Aptasensor Employing Stilbene Isomerization for Detection of Thrombin

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6927
Author(s):  
Xinling Zeng ◽  
Qing Zhou ◽  
Liyan Wang ◽  
Xiaoxian Zhu ◽  
Kuiyan Cui ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Disodium Salt ◽  
Salt Hydrate ◽  
Satisfactory Performance ◽  
Attenuation Rate ◽  
Detection Mode ◽  
One Step ◽  
Analyte Detection ◽  
Analytical Approaches ◽  
Fluorescence Kinetic

It is important to detect thrombin due to its physiological and pathological roles, where rapid and simple analytical approaches are needed. In this study, an aptasensor based on fluorescence attenuation kinetics for the detection of thrombin is presented, which incorporates the features of stilbene and aptamer. We designed and synthesized an aptasensor by one-step coupling of stilbene compound and aptamer, which employed the adaptive binding of the aptamer with thrombin to cause a change in stilbene fluorescence attenuation kinetics. The sensor realized detection of thrombin by monitoring the variation in apparent fluorescence attenuation rate constant (kapp), which could be further used for probing of enzyme–aptamer binding. In comprehensive studies, the developed aptasensor presented satisfactory performance on repeatability, specificity, and regeneration capacity, which realized rapid sensing (10 s) with a limit of detection (LOD) of 0.205 μM. The strategy was successful across seven variants of thrombin aptasensors, with tunable kapp depending on the SITS (4-Acetamido-4′-isothiocyanato-2,2′-stilbenedisulfonic acid disodium salt hydrate) grafting site. Analyte detection mode was demonstrated in diluted serum, requiring no separation or washing steps. The new sensing mode for thrombin detection paves a way for high-throughput kinetic-based sensors for exploiting aptamers targeted at clinically relevant proteins.

scholarly journals Diagnostic Mycology: Xtreme Challenges

2020 ◽  
Vol 58 (4) ◽  
Author(s):  
Brian L. Wickes ◽  
Anna M. Romanelli
Keyword(s):  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
Assay Development ◽  
Invasive Infection ◽  
Fungal Morphology ◽  
Diagnostic Assay ◽  
Diagnostic Assays ◽  
Fda Approval ◽  
United States Food ◽  
States Food

ABSTRACT Developing any diagnostic assay that receives United States Food and Drug Administration (FDA) approval can be a slow and difficult process. FDA-approved assays for fungal diagnosis are generally few in number and are focused mainly on diagnosing candidiasis, which is caused by several species of Candida, in addition to a limited number of systemic mycotic agents. While all microbial diagnostic assays face challenges before they are FDA approved and reach the market, there are a number of challenges to fungal diagnostic assay development that have been difficult hurdles to overcome. These hurdles include template preparation, fungal morphology, how many fungi should be identified in a single assay (scope), taxonomy and nomenclature, discriminating colonizers from invasive infection, combining identification with antifungal susceptibility, and navigating the administrative hurdles required to integrate an assay into a clinical laboratory. Some of these challenges are easier to overcome than others, but all seem to be particularly difficult for fungal diagnostic assays.

scholarly journals A Response to Gupta et al. (2019) Regarding the MoT3 Wheat Blast Diagnostic Assay

2019 ◽  
Vol 109 (4) ◽  
pp. 509-511 ◽  
Author(s):  
Jarred Yasuhara-Bell ◽  
Michael L. Pieck ◽  
Amy Ruck ◽  
Mark L. Farman ◽  
Gary L. Peterson ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Diagnostic Assay ◽  
Recent Letter ◽  
Diagnostic Assays ◽  
Wheat Blast ◽  
Letter To The Editor

This is a response to a recent Letter to the Editor of Phytopathology, in which Gupta et al. (2019) caution against the indiscriminate use of the MoT3 diagnostic assay that distinguishes isolates of Magnaporthe oryzae in the Triticum lineage from those that do not cause aggressive wheat blast. We confirm that the assay does reliably distinguish between wheat and rice isolates from Bangladesh and worldwide, as described in the original paper by Pieck et al. (2017) . We have been unable to reproduce the equally intense amplification of WB12 and WB12-like sequences reported in Figure 1 of the Letter. Other data presented by Gupta et al. (2019) support the specificity of the MoT3 assay. Therefore, cautions beyond those always associated with accurate reproduction of diagnostic assays are unwarranted.

scholarly journals Development of Immunochromatography-Based Methods for Detection of Leptospiral Lipopolysaccharide Antigen in Urine

2013 ◽  
Vol 20 (5) ◽  
pp. 683-690 ◽  
Author(s):  
Dian Widiyanti ◽  
Nobuo Koizumi ◽  
Takashi Fukui ◽  
Lisa T. Muslich ◽  
Takaya Segawa ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Urine Samples ◽  
Bacterial Cells ◽  
Diagnostic Assay ◽  
Healthy Individuals ◽  
Content Type ◽  
Diagnostic Assays ◽  
The World ◽  
Further Development ◽  
Study Application

ABSTRACTLeptospirosis is an infectious disease caused by the spirochete bacteriaLeptospiraspp. and is commonly found throughout the world. Diagnosis of leptospirosis performed by culture and microscopic agglutination tests is laborious and time-consuming. Therefore, we aimed to develop a novel immunochromatography (ICG)-based method for detectingLeptospiraantigen in the urine of patients and animals. We used the 1H6 monoclonal antibody (MAb), which is specific to the lipopolysaccharide (LPS) that is common amongLeptospiraspp. The MAb was coupled to 40-nm-diameter colloidal gold, and the amounts of labeled antibody and immobilized antibody were 23 μg and 2 μg per test, respectively. Several strains ofLeptospiraand other bacterial species were used to evaluate the sensitivities and specificities of the assays we developed. The detection limit of the assays was 106cells/ml when disrupted whole bacterial cells were used. The assays wereLeptospiraspecific since they did not cross-react with non-Leptospirabacteria used in the study. Application of diagnostic assays was done on the urine samples of 46Leptospira-infected hamsters, 44 patients with suspected leptospirosis, and 14 healthy individuals. Pretreatment of the urine samples by boiling and centrifugation (for ultrafiltration and concentration) eliminated nonspecific reactions that occurred in the assay. The sensitivity and specificity of the ICG-based lateral flow assay (LFA) were 89% and 87%, respectively, which were higher than those of the dipstick assay, which were 80% and 74%, respectively. In summary, this ICG-based LFA can be used as an alternative diagnostic assay for leptospirosis. Further development is still necessary to improve the assay.

Molecular Relaxation Processes in Nucleic Acids Components as Probed with Raman Spectroscopy

2017 ◽  
Vol 68 (10) ◽  
Author(s):  
Cristina M. Muntean ◽  
Ioan Bratu ◽  
Carmen Tripon ◽  
Konstantinos Nalpantidis ◽  
Monica A. P. Purcaru ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Solid Phase ◽  
Dynamical Behavior ◽  
Relaxation Times ◽  
Relaxation Mechanism ◽  
Disodium Salt ◽  
Relaxation Processes ◽  
Molecular Relaxation ◽  
Salt Hydrate ◽  
Dna And Rna

In this work the Raman total half bandwidths of five free nucleic acids components (cytidine-5`- monophosphate, 2`- deoxycytidine 5`- monophosphate, 2`- deoxyguanosine-5`- monophosphate, thymidine - 5� - monophosphate disodium salt hydrate and uridine-5`- monophosphate disodium salt) have been measured, respectively. Raman scattering can be used to study the fast molecular relaxation processes of free nucleic acids components in solid phase. The dependencies of the total half bandwidths and of the corresponding global relaxation times, on functional groups and on the type of DNA and RNA constituents, are reported. In our study, the full widths at half-maximum (FWHMs) for the Raman bands of these nucleic acids components, are typically in the wavenumber range from 9 to 28 cm-1. Besides, it can be observed that the (sub)picosecond dynamics studied in this work, has a global relaxation time value smaller than 1.18 ps and larger than 0.38 ps. We have found that the band centered at 1264 cm-1 for cytidine -5`- monophosphate, the profile near 1373 cm-1 attributed to thymidine -5`- monophosphate disodium salt hydrate and the band around 1233 cm-1 attributed to uridine -5`- monophosphate disodium salt, respectively, are suitable for studying the dynamical behavior of molecular fragments in nucleic acids components. For the case of solid phase samples of nucleic acids components, we can suppose that the dominant relaxation mechanism is of the vibrational type one.

Particle characterization of CVD tungsten metallization for 64 MBIT DRAM

1991 ◽  
Vol 49 ◽  
pp. 896-897
Author(s):  
Marylyn Bennett-Lilley ◽  
Thomas T.H. Fu ◽  
David D. Yin ◽  
R. Allen Bowling
Keyword(s):  
Chemical Vapor ◽  
Device Performance ◽  
Particle Characterization ◽  
Particle Generation ◽  
Tungsten Hexafluoride ◽  
Homogeneous Particle ◽  
Multiple Levels ◽  
Circuit Density ◽  
Sources Of Contamination

Chemical Vapor Deposition (CVD) tungsten metallization is used to increase VLSI device performance due to its low resistivity, and improved reliability over other metallization schemes. Because of its conformal nature as a blanket film, CVD-W has been adapted to multiple levels of metal which increases circuit density. It has been used to fabricate 16 MBIT DRAM technology in a manufacturing environment, and is the metallization for 64 MBIT DRAM technology currently under development. In this work, we investigate some sources of contamination. One possible source of contamination is impurities in the feed tungsten hexafluoride (WF6) gas. Another is particle generation from the various reactor components. Another generation source is homogeneous particle generation of particles from the WF6 gas itself. The purpose of this work is to investigate and analyze CVD-W process-generated particles, and establish a particle characterization methodology.

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