scholarly journals Development of Generic Immuno-Magnetic Bead-Based Enzyme-Linked Immunoassay for Ustiloxins in Rice Coupled with Enrichment

Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 907
Author(s):  
Yi Huang ◽  
Xiaoqian Tang ◽  
Lu Zheng ◽  
Junbin Huang ◽  
Qi Zhang ◽  
...  
Keyword(s):  
Magnetic Beads ◽  
High Efficiency ◽  
Detection Efficiency ◽  
Magnetic Bead ◽  
Hplc Method ◽  
Enzyme Linked Immunosorbent Assay ◽  
Common Structure ◽  
Site Monitoring ◽  
False Smut ◽  
Living Organisms

Ustiloxins are a group of mycotoxins produced by rice false smut pathogen. Previous studies have shown that the false smut balls contain six types of ustiloxins, and these toxins are toxic to living organisms. Thus, immunoassay for on-site monitoring of ustiloxins in rice is urgently required. The current immunoassays are only for detecting single ustiloxin, and they cannot meet the demand for synchronous and rapid detection of the group toxins. Therefore, this study designed and synthesized a generic antigen with ustiloxin G as material based on the common structure of the mycotoxins. Ustiloxin G was conjugated to two carrier proteins including bovine serum albumin (BSA) and ovalbvmin (OVA) by carbon diimide method. The mice were immunized with ustiloxin-G-BSA to generate the antibody serum, which was further purified to obtain the generic antibody against ustiloxins. The conjugated ustiloxin G-OVA and generic antibodies were used for establishing the enzyme-linked immunosorbent assay (ELISA) for ustiloxin detection and optimizing experiment conditions. The characterization of the antibody showed that the semi-inhibitory concentrations (IC50) of ustiloxin A, B, and G were 0.53, 0.34, and 0.06 µg/mL, respectively, and that their corresponding cross-reactivities were 11.9%, 18.4%, and 100%, respectively. To increase ELISA detection efficiency, generic antibody was combined with magnetic beads to obtain sensitive and class-specific immune-magnetic beads. Based on these immuno-magnetic beads, a high-efficiency enzyme-linked immunoassay method was developed for ustiloxin detection, whose sensitivity to ustiloxin A, B, and G was improved to 0.15 µg/mL, 0.14 µg/mL, and 0.04 µg/mL, respectively. The method accuracy was evaluated by spiking ustiloxin G as standard, and the spiked samples were tested by the immune-magnetic bead-based ELISA. The result showed the ustiloxin G recoveries ranged from 101.9% to 116.4% and were accepted by a standard HPLC method, indicating that our developed method would be promising for on-site monitoring of ustiloxins in rice.

scholarly journals Automated Panning and Screening Procedure on Microplates for Antibody Generation from Phage Display Libraries

2009 ◽  
Vol 14 (3) ◽  
pp. 282-293 ◽  
Author(s):  
Laura Turunen ◽  
Kristiina Takkinen ◽  
Hans Söderlund ◽  
Timo Pulli
Keyword(s):  
Phage Display ◽  
High Efficiency ◽  
Magnetic Bead ◽  
Enzyme Linked Immunosorbent Assay ◽  
Single Chain ◽  
Single Chain Antibody ◽  
Phage Display Technology ◽  
Antibody Phage ◽  
Antibody Phage Display ◽  
Display Technology

Antibody phage display technology is well established and widely used for selecting specific antibodies against desired targets. Using conventional manual methods, it is laborious to perform multiple selections with different antigens simultaneously. Furthermore, manual screening of the positive clones requires much effort. The authors describe optimized and automated procedures of these processes using a magnetic bead processor for the selection and a robotic station for the screening step. Both steps are performed in a 96-well microplate format. In addition, adopting the antibody phage display technology to automated platform polyethylene glycol precipitation of the enriched phage pool was unnecessary. For screening, an enzyme-linked immunosorbent assay protocol suitable for a robotic station was developed. This system was set up using human γ-globulin as a model antigen to select antibodies from a VTT naive human single-chain antibody (scFv) library. In total, 161 γ-globulin-selected clones were screened, and according to fingerprinting analysis, 9 of the 13 analyzed clones were different. The system was further tested using testosterone bovine serum albumin (BSA) and β-estradiol-BSA as antigens with the same library. In total, 1536 clones were screened from 4 rounds of selection with both antigens, and 29 different testosterone-BSA and 23 β-estradiol-BSA binding clones were found and verified by sequencing. This automated antibody phage display procedure increases the throughput of generating wide panels of target-binding antibody candidates and allows the selection and screening of antibodies against several different targets in parallel with high efficiency. ( Journal of Biomolecular Screening 2009:282-293)

scholarly journals A rapid magnetic bead-based immunoassay for sensitive determination of diclofenac

2021 ◽  
Author(s):  
Alexander Ecke ◽  
Tanja Westphalen ◽  
Jane Hornung ◽  
Michael Voetz ◽  
Rudolf J. Schneider
Keyword(s):  
Water Samples ◽  
Magnetic Beads ◽  
Limit Of Detection ◽  
Cost Effective ◽  
Magnetic Bead ◽  
Enzyme Linked Immunosorbent Assay ◽  
Reference Analysis ◽  
Immunochemical Method ◽  
Synthetic Strategy

Abstract Increasing contamination of environmental waters with pharmaceuticals represents an emerging threat for the drinking water quality and safety. In this regard, fast and reliable analytical methods are required to allow quick countermeasures in case of contamination. Here, we report the development of a magnetic bead-based immunoassay (MBBA) for the fast and cost-effective determination of the analgesic diclofenac (DCF) in water samples, based on diclofenac-coupled magnetic beads and a robust monoclonal anti-DCF antibody. A novel synthetic strategy for preparation of the beads resulted in an assay that enabled for the determination of diclofenac with a significantly lower limit of detection (400 ng/L) than the respective enzyme-linked immunosorbent assay (ELISA). With shorter incubation times and only one manual washing step required, the assay demands for remarkably shorter time to result (< 45 min) and less equipment than ELISA. Evaluation of assay precision and accuracy with a series of spiked water samples yielded results with low to moderate intra- and inter-assay variations and in good agreement with LC–MS/MS reference analysis. The assay principle can be transferred to other, e.g., microfluidic, formats, as well as applied to other analytes and may replace ELISA as the standard immunochemical method. Graphical abstract

scholarly journals Research on magnetic bead motion characteristics based on magnetic beads preset technology

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhao Li ◽  
Xiangyang Zu ◽  
Zhe Du ◽  
Zhigang Hu
Keyword(s):  
Magnetic Field ◽  
Magnetic Beads ◽  
Permanent Magnets ◽  
Detection Efficiency ◽  
Mixing Time ◽  
Magnetic Bead ◽  
Motion Models ◽  
Motion Characteristics ◽  
Control Principle ◽  
The Relationship

AbstractIn order to improve the detection efficiency and accuracy of microfluidic chip, a magnetic beads preset technology were designed by using double permanent magnets as external magnetic field and the motion characteristics of preset magnetic beads were studied. The control principle of magnetic beads preset technology was introduced in detail, and the control structure was designed. The coupled field characteristics for magnetic beads in microchannels were analyzed, and the motion models of magnetic beads were established based on the magnetic beads preset technology, including capture motion and mixing motion. The relationship between the magnetic field force and the flow velocity for capturing magnetic bead, and the mixing time under the influence of flow field and magnetic field were derived. The magnetic beads preset technology effect was verified by experiments and numerical simulations were developed to analyze the influence of aspect ratio of permanent magnet on magnetic field. The study showed that the accuracy and efficiency of the magnetic bead control in the microchannel could be better realized by the magnetic beads preset technology. The derivation of the magnetic bead motion model can understand the motion characteristics of the magnetic bead more clearly, facilitate accurate control of the magnetic bead, and improve the success rate of the microfluidic detection.

scholarly journals Research on Magnetic Bead Motion Characteristics based on Magnetic Beads Preset Technology

2021 ◽  
Author(s):  
Zhao Li ◽  
Xiangyang Zu ◽  
Zhe Du ◽  
Zhigang Hu
Keyword(s):  
Magnetic Field ◽  
Magnetic Beads ◽  
Permanent Magnets ◽  
Detection Efficiency ◽  
Mixing Time ◽  
Magnetic Bead ◽  
Motion Models ◽  
Motion Characteristics ◽  
Control Principle ◽  
The Relationship

Abstract In order to improve the detection efficiency and accuracy of microfluidic chip, a magnetic beads preset technology were designed by using double permanent magnets as external magnetic field and the motion characteristics of preset magnetic beads were studied. The control principle of magnetic beads preset technology was introduced in detail, and the control structure was designed. The coupled field characteristics for magnetic beads in microchannels were analyzed, and the motion models of magnetic beads were established based on the bead preset technology, including capture motion and mixing motion. The relationship between the magnetic field force and the flow velocity for capturing magnetic bead, and the mixing time under the influence of flow field and magnetic field were derived. The magnetic beads capture effect of magnetic beads preset technology was verified by experiments. The study showed the magnetic beads preset technology can better realize the accuracy and efficiency of the magnetic bead control in the microchannel. The derivation of the magnetic bead motion model can understand the motion characteristics of the magnetic bead more clearly, facilitate accurate control of the magnetic bead, and improve the success rate of the microfluidic detection.

Loop-mediated Isothermal Amplification for Rapid Detection of Mating Types of Villosiclava virens

Plant Disease ◽  
2021 ◽  
Author(s):  
Xiayan Pan ◽  
Xiao Wang ◽  
Junjie Yu ◽  
Mina Yu ◽  
Huijuan Cao ◽  
...  
Keyword(s):  
Mating Type ◽  
Genomic Dna ◽  
High Efficiency ◽  
Lamp Assay ◽  
Isothermal Amplification ◽  
Loop Mediated Isothermal Amplification ◽  
Villosiclava Virens ◽  
False Smut ◽  
Mating Type Genes ◽  
Polymerase Chain

Rice false smut (RFS), caused by Villosiclava virens, is an important fungal disease in panicle of rice. V. virens is a heterothallic ascomycete that controlled by two opposite idiomorphs, MAT1-1 and MAT1-2. Previous study showed sexual reproduction of V. virens plays an important role in the epidemic of RFS. In this study, we have developed a loop-mediated isothermal amplification (LAMP) assay to detect mating type of V. virens easily and rapidly by using specific primers designed on the mating type genes MAT1-1-2 and MAT1-2-1, respectively. The LAMP assay required only a water/dry bath and could recognize the mating type of V. virens in just 45 min. The LAMP assay was so sensitive that could detect small amounts of V. virens genomic DNA (as low as 2.0 pg of MAT1-1, and 200.0 pg of MAT1-2), which was 10-fold more sensitive than polymerase chain reaction (PCR). In addition, the application of mating type using LAMP assay was demonstrated feasibly by assessing the genomic DNA of V. virens isolated from rice fields. The high efficiency and specificity of this LAMP assay suggested it can be used as a rapid testing tool in mating type recognition of V. virens isolates in the field.

The Research of a New Method for Manipulating Magnetic Beads through Multi-Layered Flat Micro-Coils Coupled with Permanent Magnet

2013 ◽  
Vol 753-755 ◽  
pp. 1571-1575
Author(s):  
Zhi Hua Liu ◽  
Yu Feng Huang ◽  
Jian Peng Li ◽  
Xin Wei Xu
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Flow Velocity ◽  
Magnetic Beads ◽  
Magnetic Bead ◽  
New Method ◽  
Viscous Resistance ◽  
Main Factors ◽  
The Magnetic Field

Magnetic bead droplet's non-contacted manipulation can be realized in Electromagnetic MEMS, but how to achieve magnetic beads manipulation is the major problem. A new method of multi-layered flat coils coupled with permanent magnet was proposed. Firstly, the theory of magnetic bead manipulation was analyzed and the main factors affected the magnetic beads manipulation was identified; then the magnetic field of multi-layered flat coils and Stokes viscous resistance of magnetic beads were analyzed and simulated quantificationally; finally the magnetic bead capture area was got under different flow velocity. Consequently the feasibility and correctness of this method was verified.

scholarly journals The Magnetic Bead Computing Model of the 0-1 Integer Programming Problem Based on DNA Cycle Hybridization

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Rujie Xu ◽  
Zhixiang Yin ◽  
Zhen Tang ◽  
Jing Yang ◽  
Jianzhong Cui ◽  
...  
Keyword(s):  
Integer Programming ◽  
Programming Problem ◽  
Magnetic Beads ◽  
Specific Binding ◽  
Optimal Solution ◽  
High Sensitivity ◽  
Magnetic Bead ◽  
Integer Programming Problem ◽  
Computing Model ◽  
Dna Strands

Magnetic beads and magnetic Raman technology substrates have good magnetic response ability and surface-enhanced Raman technology (SERS) activity. Therefore, magnetic beads exhibit high sensitivity in SERS detection. In this paper, DNA cycle hybridization and magnetic bead models are combined to solve 0-1 integer programming problems. First, the model maps the variables to DNA strands with hairpin structures and weights them by the number of hairpin DNA strands. This result can be displayed by the specific binding of streptavidin and biotin. Second, the constraint condition of the 0-1 integer programming problem can be accomplished by detecting the signal intensity of the biological barcode to find the optimal solution. Finally, this model can be used to solve the general 0-1 integer programming problem and has more extensive applications than the previous DNA computing model.

An integrated microfluidic system for on-chip enrichment and quantification of circulating extracellular vesicles from whole blood

Lab on a Chip ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 3305-3315 ◽  
Author(s):  
Yi-Sin Chen ◽  
Yu-Dong Ma ◽  
Chihchen Chen ◽  
Shu-Chu Shiesh ◽  
Gwo-Bin Lee
Keyword(s):  
Extracellular Vesicles ◽  
Immunosorbent Assay ◽  
Whole Blood ◽  
Magnetic Beads ◽  
Extracellular Vesicle ◽  
Microfluidic System ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Whole Blood ◽  
On Chip ◽  
Chip Enrichment

An integrated microfluidic system was developed for extracellular vesicle (EV) enrichment and quantification by using anti-CD63-coated magnetic beads and an on-chip enzyme-linked immunosorbent assay in human whole blood.

scholarly journals Large High-Efficiency Thermal Neutron Detectors Based on the Micromegas Technology

Universe ◽  
2018 ◽  
Vol 4 (12) ◽  
pp. 134 ◽  
Author(s):  
Georgios Tsiledakis ◽  
Alain Delbart ◽  
Daniel Desforge ◽  
Ioanis Giomataris ◽  
Thomas Papaevangelou ◽  
...  
Keyword(s):  
Thermal Neutron ◽  
Large Scale ◽  
High Efficiency ◽  
Detection Efficiency ◽  
Rate Capability ◽  
High Rate ◽  
Thermal Neutrons ◽  
Neutron Detectors ◽  
Electron Multiplier ◽  
Detection Techniques

Due to the so-called 3He shortage crisis, many detection techniques for thermal neutrons are currently based on alternative converters. There are several possible ways of increasing the detection efficiency for thermal neutrons using the solid neutron-to-charge converters 10B or 10B4C. Here, we present an investigation of the Micromegas technology. The micro-pattern gaseous detector Micromegas was developed in the past years at Saclay and is now used in a wide variety of neutron experiments due to its combination of high accuracy, high rate capability, excellent timing properties, and robustness. A large high-efficiency Micromegas-based neutron detector is proposed for thermal neutron detection, containing several layers of 10B4C coatings that are mounted inside the gas volume. The principle and the fabrication of a single detector unit prototype with overall dimension of ~15 × 15 cm2 and its possibility to modify the number of 10B4C neutron converter layers are described. We also report results from measurements that are verified by simulations, demonstrating that typically five 10B4C layers of 1–2 μm thickness would lead to a detection efficiency of 20% for thermal neutrons and a spatial resolution of sub-mm. The high potential of this novel technique is given by the design being easily adapted to large sizes by constructing a mosaic of several such detector units, resulting in a large area coverage and high detection efficiencies. An alternative way of achieving this is to use a multi-layered Micromegas that is equipped with two-side 10B4C-coated gas electron multiplier (GEM)-type meshes, resulting in a robust and large surface detector. Another innovative and very promising concept for cost-effective, high-efficiency, large-scale neutron detectors is by stacking 10B4C-coated microbulk Micromegas. A prototype was designed and built, and the tests so far look very encouraging.

Polyclonal Antibody-Based ELISA and HPLC Methods for the Determination of Fumonisins in Corn: A Comparative Study

1996 ◽  
Vol 59 (8) ◽  
pp. 893-897 ◽  
Author(s):  
ERIC W. SYDENHAM ◽  
SONJA STOCKENSTRÖM ◽  
PIETER G. THIEL ◽  
JOHN P. RHEEDER ◽  
M. BRUNO DOKO ◽  
...  
Keyword(s):  
Comparative Study ◽  
Polyclonal Antibody ◽  
High Performance ◽  
Linear Regression Analysis ◽  
Correlation Coefficients ◽  
Hplc Method ◽  
Enzyme Linked Immunosorbent Assay ◽  
Regression Slopes ◽  
The Individual ◽  
The Comparative Study

The performance of an experimental polyclonal antibody (PAb)-based competitive direct enzyme-linked immunosorbent assay (CD-ELISA) developed for the analysis of fumonisins in corn was assessed by comparison with an established high-performance liquid chromatography (HPLC) method. The comparative study was conducted using a series of 20 corn samples naturally contaminated with combined fumonisin levels ranging from &lt;0.05 to &gt;5 μg/g (ppm). Linear regression analysis between the results generated by HPLC and CD-ELISA provided correlation coefficients (r) and regression slopes (b) of r = 0.960, b = 1.493 (P &lt; 0.001); r = 0.865, b = 3.903 (P &lt; 0.001); and r = 0.832, b = 0.107 (P &lt; 0.001) for the individual fumonisins B1 (FB1), B2 (FB2) and B3 (FB3), respectively, while corresponding values of r = 0.967, b = 1.059 (P &lt; 0.001) were obtained for the combined FB1, FB2, and FB3 concentrations. In 3 of 18 fumonisin-positive corn samples, combined fumonisin levels determined by CD-ELISA were between 85 and 100% higher than those determined in the same extracts by HPLC, while in 13 other samples, CD-ELISA results were between 1.8 and 53% higher than those determined by HPLC. Conversely, in 2 of 18 samples, CD-ELISA results were lower than those determined by HPLC. The differences recorded between HPLC and the experimental PAb-based CD-ELISA were far less than those previously recorded for other mono- and polyclonal antibody-based CD-ELISA systems. The results indicate that the experimental PAb-based CD-ELISA may be effectively applied for the initial screening for fumonisins in corn.

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