scholarly journals Multiplex Detection of Magnetic Beads Using Offset Field Dependent Frequency Mixing Magnetic Detection

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5859
Author(s):  
Ali Mohammad Pourshahidi ◽  
Stefan Achtsnicht ◽  
Mrinal Murali Nambipareechee ◽  
Andreas Offenhäusser ◽  
Hans-Joachim Krause
Keyword(s):  
Magnetic Beads ◽  
Programming Algorithm ◽  
Quantitative Detection ◽  
Multiplex Detection ◽  
Mixing Ratios ◽  
Field Dependent ◽  
Sample Amount ◽  
Magnetic Detection ◽  
Mixture Samples ◽  
Frequency Mixing

Magnetic immunoassays employing Frequency Mixing Magnetic Detection (FMMD) have recently become increasingly popular for quantitative detection of various analytes. Simultaneous analysis of a sample for two or more targets is desirable in order to reduce the sample amount, save consumables, and save time. We show that different types of magnetic beads can be distinguished according to their frequency mixing response to a two-frequency magnetic excitation at different static magnetic offset fields. We recorded the offset field dependent FMMD response of two different particle types at frequencies f1 + n⋅f2, n = 1, 2, 3, 4 with f1 = 30.8 kHz and f2 = 63 Hz. Their signals were clearly distinguishable by the locations of the extremes and zeros of their responses. Binary mixtures of the two particle types were prepared with different mixing ratios. The mixture samples were analyzed by determining the best linear combination of the two pure constituents that best resembled the measured signals of the mixtures. Using a quadratic programming algorithm, the mixing ratios could be determined with an accuracy of greater than 14%. If each particle type is functionalized with a different antibody, multiplex detection of two different analytes becomes feasible.

Magnetic immunoassay based on frequency mixing magnetic detection and magnetic particles of different magnetic properties

2014 ◽  
Vol 6 (19) ◽  
pp. 8055-8058 ◽  
Author(s):  
H. B. Hong ◽  
H.-J. Krause ◽  
I. H. Nam ◽  
C. J. Choi ◽  
S. W. Shin
Keyword(s):  
Magnetic Properties ◽  
Magnetic Particles ◽  
Different Types ◽  
Magnetic Detection ◽  
Analytical System ◽  
Frequency Mixing

A novel analytical system is presented that employs two different types of magnetic particles (MPs) with frequency mixing magnetic detection (FMMD).

Quantum Dots as Fluorescent Labels for Quantitative Detection of Salmonella Typhimurium in Chicken Carcass Wash Water

2005 ◽  
Vol 68 (6) ◽  
pp. 1241-1245 ◽  
Author(s):  
LIJU YANG ◽  
YANBIN LI
Keyword(s):  
Quantum Dots ◽  
Salmonella Typhimurium ◽  
Pathogenic Bacteria ◽  
Magnetic Beads ◽  
Cell Number ◽  
Wash Water ◽  
Quantitative Detection ◽  
Fluorescent Labels ◽  
Microbial Detection ◽  
Chicken Carcass

Fluorescent semiconductor quantum dots have recently emerged as a novel and promising class of fluorescent labels for biological detection. In this study, quantum dots were used as fluorescent labels in immunoassays for quantitative detection of foodborne pathogenic bacteria. Salmonella Typhimurium cells were separated from chicken carcass wash water using anti-Salmonella antibody coated magnetic beads and reacted to secondary biotin-labeled anti-Salmonella antibody. Quantum dots coated with streptavidin were added to react with biotin on the secondary antibody. Measurement of the intensity of fluorescence produced by quantum dots provided a quantitative method for microbial detection. A linear relationship between Salmonella Typhimurium cell number (log N) in the samples of chicken carcass wash water and the fluorescence intensity (FI) was found for the cell numbers ranging from 103 to 107 CFU/ml. The regression model can be expressed as FI = 198.6 Log N − 639.03 with R2 = 0.96. The detection limit of this method was 103 CFU/ml.

scholarly journals The Multiple Infections of Porcine Diarrhea Viruses in Local Area Based on A Luminex xTAG Multiplex Detection Method

2020 ◽  
Author(s):  
Huili liu ◽  
Ying Shi ◽  
Benqiang Li ◽  
Jie Tao ◽  
Jinghua Cheng
Keyword(s):  
Detection Method ◽  
Southern China ◽  
Local Area ◽  
Clinical Samples ◽  
Multiple Infections ◽  
Quantitative Detection ◽  
Multiplex Detection ◽  
Viral Diarrhea ◽  
Infection Pattern ◽  
Pcr Method

Abstract Background Porcine viral diarrhea can cause great damage to the pig industry. However, multiple infections have contributed to the poor control of diarrhea, which has also resulted in great difficulties in determining the main pathogenic factors. Methods A Luminex xTAG multiplex detection method was developed for the detection of 11 viral diarrhea pathogens, which allows for the simultaneous qualitative and quantitative detection of viral diarrhea pathogens in clinical samples. A total of 518 porcine stool specimens were collected from 9 pig herds in Shanghai, China from 2015 to 2017, and the pathogen spectrums and co-infections were analyzed. Results The minimum detection rate of the Luminex xTAG multiplex detection method was at least 10 times higher than the traditional PCR method. Of the 518 diarrhea samples, PEDV was found in 17.57% (91/518), PKoV in 40.35% (209/518), PAstV in 26.64% (138/518), PSV in 15.06% (78/518), PoSaV in 13.13% (68/518), PTV in 5.21% (27/518), PDCoV in 4.83% (25/518), PoRV in 3.28% (17/518), TGEV in 3.09% (16/518), PToV in 1.93% (10/518), and BVDV in 1.74% (9/518), respectively. Furthermore, multiple infections were commonly seen, with positive rate of 35.14%. Infection pattern of the viral diarrheal pathogens in a specific farm was changing, and different farms had the various diarrhea infection patterns. A longitudinal investigation showed that PEDV was still the key pathogen which was closely related to the death of diarrhea piglets. Other pathogens might play synergistic roles in the pathogenesis of diarrhea disease. Conclusions Here we provided a Luminex xTAG multiple detection method for viral diarrhea pathogen infection in clinical, which was more sensitive and specific than general multiplex PCR method. Furthermore, the surveillance confirmed high infection rate of PKoV, but PEDV was still the key pathogen and multiple pathogens synergistically complicated the infection status in southern China, suggesting that controlling porcine diarrhea might be more complex than previously thought. A better understanding of viruses that cause diarrhea in piglets will aid in better preventing and controlling epidemics of viral porcine diarrhea.

scholarly journals Epidemiological analysis of Porcine Viral Diarrhea Pathogens in Local Area

2020 ◽  
Author(s):  
Ying Shi ◽  
Benqiang Li ◽  
Jie Tao ◽  
Jinghua Cheng ◽  
Huili liu
Keyword(s):  
Prevention And Control ◽  
Detection Method ◽  
Multiple Infection ◽  
Clinical Samples ◽  
Quantitative Detection ◽  
Multiplex Detection ◽  
Diarrhea Virus ◽  
Viral Diarrhea ◽  
Pcr Method ◽  
And Control

Abstract Background Porcine viral diarrhea can cause great damage to the pig industry and high mortality to piglets. Furthermore, multiple pathogen infections and synergistic infections commonly existed in clinic. This has resulted in great difficulties in determining the main pathogenic factors, which would delay the prevention and control of diseases. Methods A total of 518 porcine stool specimens were collected from 9 pig herds in Shanghai, China from 2015 to 2017 and used for pathogen detection. A Luminex xTAG multiplex detection method was developed for the detection of 11 viral diarrhea pathogens, which allows for the simultaneous qualitative and quantitative detection of viral diarrhea pathogens in clinical samples. Results The minimum detection rate of the Luminex xTAG multiplex detection method was at least 10 times higher than the traditional PCR method. As a result, 209 (40.3%) were positive for porcine kobuvirus (PKoV), 138 (26.6%) for porcine astrovirus (PAstV), 91 (17.6%) for porcine epidemic diarrhea virus (PEDV), 78 (15.1%) for porcine sapelovirus (PSV), 68 (13.1%) for porcine sapovirus (PoSaV), 27 (5.2%) for porcine teschovirus (PTV), 25 (4.8%) for porcine deltacoronavirus (PDCoV), 17 (3.3%) for porcine rotavirus (PoRV), 16 (3.1%) for transmissible gastroenteritis virus (TGEV), 10 (1.9%) for porcine torovirus (PToV), and 9 (1.7%) for bovine viral diarrhea virus (BVDV), respectively. Furthermore, multiple infection rate of diarrhea sample was 17.57% for dual-infection, 11.58%for triple-infection, 4.63% for quadruple-infection, 0.77% for quintuple-infection, 0.58% for sextuple-infection and septuple-infection, respectively. Infection pattern of the viral diarrheal pathogens was changing, and different farm had the various diarrhea infection patterns, which proved the great importance of epidemiological surveillance and the guidance effect to clinical production. PoSaV, PoRV, PAstV, PToV and PEDV were indicated as the predominant viruses of clinical samples collected in 2017 by the quantitative analysis. Conclusions Here we provide a Luminex xTAG multiple detection method for viral diarrhea pathogen infection in clinical,which was more sensitive and specific than general multiplex PCR method. Furthermore, the surveillance confirmed the complicated infection status in China, which demonstrated the need for continuous surveillance and provided data for the prevention and control of viral diarrhea.

scholarly journals Detection of deep stratospheric intrusions by cosmogenic 35S

2016 ◽  
Vol 113 (40) ◽  
pp. 11131-11136 ◽  
Author(s):  
Mang Lin ◽  
Lin Su ◽  
Robina Shaheen ◽  
Jimmy C. H. Fung ◽  
Mark H. Thiemens
Keyword(s):  
Air Quality ◽  
Southern California ◽  
Ground Level ◽  
Ambient Air ◽  
Quality Standard ◽  
Quantitative Detection ◽  
Daily Maximum ◽  
Model Calculations ◽  
Mixing Ratios ◽  
Stratospheric Intrusions

The extent to which stratospheric intrusions on synoptic scales influence the tropospheric ozone (O3) levels remains poorly understood, because quantitative detection of stratospheric air has been challenging. Cosmogenic 35S mainly produced in the stratosphere has the potential to identify stratospheric air masses at ground level, but this approach has not yet been unambiguously shown. Here, we report unusually high 35S concentrations (7,390 atoms m−3; ∼16 times greater than annual average) in fine sulfate aerosols (aerodynamic diameter less than 0.95 µm) collected at a coastal site in southern California on May 3, 2014, when ground-level O3 mixing ratios at air quality monitoring stations across southern California (43 of 85) exceeded the recently revised US National Ambient Air Quality Standard (daily maximum 8-h average: 70 parts per billion by volume). The stratospheric origin of the significantly enhanced 35S level is supported by in situ measurements of air pollutants and meteorological variables, satellite observations, meteorological analysis, and box model calculations. The deep stratospheric intrusion event was driven by the coupling between midlatitude cyclones and Santa Ana winds, and it was responsible for the regional O3 pollution episode. These results provide direct field-based evidence that 35S is an additional sensitive and unambiguous tracer in detecting stratospheric air in the boundary layer and offer the potential for resolving the stratospheric influences on the tropospheric O3 level.

Magnetic particle imaging with a planar frequency mixing magnetic detection scanner

2014 ◽  
Vol 85 (1) ◽  
pp. 013705 ◽  
Author(s):  
Hyobong Hong ◽  
Jaeho Lim ◽  
Chel-Jong Choi ◽  
Sung-Woong Shin ◽  
Hans-Joachim Krause
Keyword(s):  
Magnetic Particle ◽  
Magnetic Particle Imaging ◽  
Magnetic Detection ◽  
Particle Imaging ◽  
Frequency Mixing

Asymmetric bead aggregation for microfluidic immunodetection

Lab on a Chip ◽  
2017 ◽  
Vol 17 (12) ◽  
pp. 2095-2103 ◽  
Author(s):  
Sunggu Kim ◽  
Sanghoon Han ◽  
Junghoon Lee
Keyword(s):  
Magnetic Beads ◽  
Quantitative Detection ◽  
Sliding Motion ◽  
Target Analytes

We present the asymmetric immunoaggregation between polystyrene and magnetic beads, which enables quantitative detection of target analytes via sliding motion in a flow.

scholarly journals Amperometric Detection ofBacillus anthracisSpores: A Portable, Low-Cost Approach to the ELISA

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Gabriel D. Peckham ◽  
Brian E. Hew ◽  
David F. Waller ◽  
Charlie Holdaway ◽  
Michael Jen
Keyword(s):  
Glucose Oxidase ◽  
Magnetic Beads ◽  
Low Cost ◽  
Amperometric Detection ◽  
Signal Generation ◽  
Quantitative Detection ◽  
Laptop Computer ◽  
Electron Mediator ◽  
Fluorescent Signal ◽  
Flow Devices

Antibody-based detection assays are generally robust, a desirable characteristic for in-the-field use. However, to quantify the colorimetric or fluorescent signal, these assays require expensive and fragile instruments which are ill-suited to in-the-field use. Lateral flow devices (LFDs) circumvent these barriers to portability but suffer from poor sensitivity and subjective interpretation. Here, an antibody-based method for detectingBacillus anthracisspores via amperometric signal generation is compared to ELISA and LFDs. This amperometric immunoassay uses antibody conjugated to magnetic beads and glucose oxidase (GOX) along with the electron mediator 2, 6-dichlorophenolindophenol (DCPIP) for production of a measurable current from a 0.4 V bias voltage. With similar sensitivity to ELISA, the assay can be completed in about 75 minutes while being completely powered and operated from a laptop computer. Immunoassay amperometry holds promise for bringing low-cost, quantitative detection of hazardous agents to the field.

scholarly journals New Uses for the Personal Glucose Meter: Detection of Nucleic Acid Biomarkers for Prostate Cancer Screening

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5514
Author(s):  
Clara Abardía-Serrano ◽  
Rebeca Miranda-Castro ◽  
Noemí de-los-Santos-Álvarez ◽  
María Jesús Lobo-Castañón
Keyword(s):  
Prostate Cancer ◽  
Cancer Screening ◽  
Nucleic Acid ◽  
Magnetic Beads ◽  
Dynamic Range ◽  
Prostate Cancer Screening ◽  
Biological Fluids ◽  
Quantitative Detection ◽  
Personal Glucose Meter ◽  
Glucose Meter

A personal glucose meter (PGM)-based method for quantitative detection of a urinary nucleic acid biomarker in prostate cancer screening, the so-called PCA3, is reported herein. A sandwich-type genoassay is conducted on magnetic beads to collect the target from the sample by specific hybridization, making the assay appropriate for PCA3 detection in biological fluids. The success of the method hinges on the use of alkaline phosphatase (ALP) to link the amount of nucleic acid biomarker to the generation of glucose. In particular, specifically attached ALP molecules hydrolyze D-glucose-1-phosphate into D-glucose, thus enabling the amplification of the recorded signal on the personal glucose meter. The developed genoassay exhibits good sensitivity (3.3 ± 0.2 mg glucose dL−1 pM−1) for PCA3, with a dynamic range of 5 to 100 pM and a quantification limit of 5 pM. Likewise, it facilitates point-of-care testing of nucleic acid biomarkers by using off-the-shelf PGM instead of complex instrumentation involved in traditional laboratory-based tests.

Quantitative detection of ZAP-70 expression in chronic lymphocytic leukemia.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 6581-6581
Author(s):  
Peixuan Zhu ◽  
Heba A Degheidy ◽  
Gerald E Marti ◽  
Shuhong Li ◽  
Fatima Abbasi ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Magnetic Beads ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Lymphocytic Leukemia ◽  
Jurkat Cells ◽  
Leukemic Cells ◽  
Quantitative Detection ◽  
Fluorescence Signal ◽  
Wide Range

6581 Background: Intracellular ZAP-70 protein was recently recognized as prognostic marker in chronic lymphocytic leukemia (CLL). The specific objective of this study was to develop a simple and sensitive assay, for the quantitative detection of ZAP-70 protein in leukemic cells. Methods: Components of the assay system include sample preparation, immunomagnetic fluorescence assay, Signalyte-II spectrofluorometer. The leukemic cells were isolated from CLL patient blood samples and lysed to release the intracellular ZAP-70 protein. ZAP-70 protein was captured by magnetic beads coated with anti-ZAP70 capture antibody, and recognized by a fluorescent detector antibody, forming an immuno-sandwich complex. This complex was dissociated for measurement of the fluorescence signal, which was proportional to ZAP-70 concentration, using the spectrofluorometer. Results: The assay conditions were extensively optimized by selecting an optimal pair of capture/detector antibodies, conjugation of fluorescence dye, cell lysis condition and excitation/emission wavelengths. The protocol was further validated with two positive controls, Jurkat cell lysate and recombinant ZAP70 protein (rZAP70). The limit of detection was determined to be lower than 125 Jurkat cells and 39 pg of rZAP70 protein. The signal response was linear over a wide range of concentration, from 625 to 40,000 Jurkat cells per test (R2=0.9987) and from 0 to 40,000 pg rZAP70 protein per test (R2=0.9928). The results from 20 CLL patients correlated strongly with flow cytometry analysis. The concordance between the two methods for positive and negative results was 100% (7/7) and 92% (12/13), respectively, while the overall concordance between the two methods was 95%. Conclusions: The assay is a simple, reliable, and reproducible method for quantitative detection of ZAP-70 in patient leukemic cells, without the need for cell fixation or permeabilization. The entire assay could be completed in 5.5 hours. The ZAP-70 signal was linear over a wide dynamic range, which we believe enables quantitative assessment of small changes in ZAP-70 expression over the course of the disease and in response to therapeutic intervention.

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