scholarly journals A Critical Comparison between Flow-through and Lateral Flow Immunoassay Formats for Visual and Smartphone-Based Multiplex Allergen Detection

Biosensors ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 143 ◽  
Author(s):  
Georgina M. S. Ross ◽  
Gert IJ. Salentijn ◽  
Michel W. F. Nielen
Keyword(s):  
Test Line ◽  
Color Space ◽  
Lateral Flow ◽  
Critical Comparison ◽  
Passive Flow ◽  
Allergen Detection ◽  
Assay Time ◽  
Flow Through ◽  
Allergen Labeling ◽  
Active Flow

(1) Background: The lack of globally standardized allergen labeling legislation necessitates consumer-focused multiplexed testing devices. These should be easy to operate, fast, sensitive and robust. (2) Methods: Herein, we describe the development of three different formats for multiplexed food allergen detection, namely active and passive flow-through assays, and lateral flow immunoassays with different test line configurations. (3) Results: The fastest assay time was 1 min, whereas even the slowest assay was within 10 min. With the passive flow approach, the limits of detection (LOD) of 0.1 and 0.5 ppm for total hazelnut protein (THP) and total peanut protein (TPP) in spiked buffer were reached, or 1 and 5 ppm of THP and TPP spiked into matrix. In comparison, the active flow approach reached LODs of 0.05 ppm for both analytes in buffer and 0.5 and 1 ppm of THP and TPP spiked into matrix. The optimized LFIA configuration reached LODs of 0.1 and 0.5 ppm of THP and TPP spiked into buffer or 0.5 ppm for both analytes spiked into matrix. The optimized LFIA was validated by testing in 20 different blank and spiked matrices. Using device-independent color space for smartphone analysis, two different smartphone models were used for the analysis of optimized assays.

Enhanced vortex stability in trapped vortex combustor

2010 ◽  
Vol 114 (1155) ◽  
pp. 333-337 ◽  
Author(s):  
S. Vengadesan ◽  
C. Sony
Keyword(s):  
Numerical Simulation ◽  
Vortex Flow ◽  
Cavity Size ◽  
Vortex Stability ◽  
Cold Flow ◽  
Air Jets ◽  
Passive Flow ◽  
Flow Through ◽  
Trapped Vortex ◽  
Driver Air

Abstract The Trapped Vortex Combustor (TVC) is a new design concept in which cavities are designed to trap a vortex flow structure established through the use of driver air jets located along the cavity walls. TVC offers many advantages when compared to conventional swirl-stabilised combustors. In the present work, numerical investigation of cold flow (non-reacting) through the two-cavity trapped vortex combustor is performed. The numerical simulation involves passive flow through the two-cavity TVC to obtain an optimum cavity size to trap stable vortices inside the second cavity and to observe the characteristics of the two cavity TVC. From the flow attributes, it is inferred that vortex stability is achieved by circulation and the vortex is trapped inside when a second afterbody is added.

scholarly journals The Efficiency of Color Space Channels to Quantify Color and Color Intensity Change in Liquids, pH Strips, and Lateral Flow Assays with Smartphones

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5104 ◽  
Author(s):  
Nelis ◽  
Bura ◽  
Zhao ◽  
Burkin ◽  
Rafferty ◽  
...  
Keyword(s):  
Color Space ◽  
Intensity Variation ◽  
Lateral Flow ◽  
Background Correction ◽  
Intensity Change ◽  
Prediction Errors ◽  
End User ◽  
Color Intensity ◽  
Soil Extracts ◽  
Lateral Flow Assays

Bottom-up, end-user based feed, and food analysis through smartphone quantification of lateral flow assays (LFA) has the potential to cause a paradigm shift in testing capabilities. However, most developed devices do not test the presence of and implications of inter-phone variation. Much discussion remains regarding optimum color space for smartphone colorimetric analyses and, an in-depth comparison of color space performance is missing. Moreover, a light-shielding box is often used to avoid variations caused by background illumination while the use of such a bulky add-on may be avoidable through image background correction. Here, quantification performance of individual channels of RGB, HSV, and LAB color space and ΔRGB was determined for color and color intensity variation using pH strips, filter paper with dropped nanoparticles, and colored solutions. LAB and HSV color space channels never outperformed the best RGB channels in any test. Background correction avoided measurement variation if no direct sunlight was used and functioned more efficiently outside a light-shielding box (prediction errors < 5%/35% for color/color intensity change). The system was validated using various phones for quantification of major allergens (i.e., gluten in buffer, bovine milk in goat milk and goat cheese), and, pH in soil extracts with commercial pH strips and LFA. Inter-phone variation was significant for LFA quantification but low using pH strips (prediction errors < 10% for all six phones compared). Thus, assays based on color change hold the strongest promise for end-user adapted smartphone diagnostics.

scholarly journals Rapid one-step enzyme immunoassay and lateral flow immunochromatographic assay for colistin in animal feed and food

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jiayi Wang ◽  
Jinyu Zhou ◽  
Yiqiang Chen ◽  
Xinpei Zhang ◽  
Yongpeng Jin ◽  
...  
Keyword(s):  
Animal Feed ◽  
Animal Production ◽  
Lateral Flow ◽  
Immunochromatographic Assay ◽  
Animal Origin ◽  
Quantitative Detection ◽  
One Step ◽  
Assay Time ◽  
Animal Origin Food ◽  
Lateral Flow Immunochromatographic Assay

Abstract Background Colistin (polymyxin E) is a kind of peptide antibiotic which has been approved in animal production for the purposes of disease prevention, treatment, and growth promotion. However, the wide use of colistin in animal feed may accelerate the spread of colistin-resistance gene MCR-1 from animal production to human beings, and its residue in animal-origin food may also pose serious health hazards to humans. Thus, it is necessary to develop corresponding analytical methods to monitor the addition of colistin in animal feed and the colistin residue in animal-origin food. Results A one-step enzyme-linked immunosorbent assay (ELISA) and a lateral flow immunochromatographic assay (LFIA) for colistin were developed based on a newly developed monoclonal antibody. The ELISA showed a 50% inhibition value (IC50) of 9.7 ng/mL with assay time less than 60 min, while the LFIA had a strip reader-based detection limit of 0.87 ng/mL in phosphate buffer with assay time less than 15 min. For reducing the non-specific adsorption of colistin onto sample vial, the components of sample extraction solution were optimized and proved to greatly improve the assay accuracy. The spiked recovery experiment showed that the recoveries of colistin from feed, milk and meat samples were in the range of 77.83% to 113.38% with coefficient of variations less than 13% by ELISA analysis and less than 18% by LFIA analysis, respectively. Furthermore, actual sample analysis indicated that the two immunoassays can produce results consistent with instrumental analysis. Conclusions The developed assays can be used for rapid qualitative or quantitative detection of colistin in animal feed and food.

Lateral-Flow Effect on Endwall Heat Transfer and Pressure Drop in a Pin-Fin Trapezoidal Duct of Various Pin Shapes

2000 ◽  
Vol 123 (1) ◽  
pp. 133-139 ◽  
Author(s):  
Jenn-Jiang Hwang ◽  
Chau-Ching Lu
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Pressure Drop ◽  
Flow Rate ◽  
Lateral Flow ◽  
Transfer Enhancement ◽  
Pin Fin ◽  
Flow Reynolds Number ◽  
Outlet Flow ◽  
Flow Through

The effects of lateral-flow ejection 0<ε<1.0, pin shapes (square, diamond, and circular), and flow Reynolds number (6000<Re<40,000) on the endwall heat transfer and pressure drop for turbulent flow through a pin-fin trapezoidal duct are studied experimentally. A staggered pin array of five rows and five columns is inserted in the trapezoidal duct, with the same spacings between the pins in the streamwise and spanwise directions: Sx/d=Sy/d=2.5. Three different-shaped pins of length from 2.5<l/d<4.6 span the distance between two endwalls of the trapezoidal duct. Results reveal that the pin-fin trapezoidal duct with lateral-flow rate of ε=0.3-0.4 has a local minimum endwall-averaged Nusselt number and Euler number for all pin shapes investigated. The trapezoidal duct of lateral outlet flow only (ε=1.0) has the highest endwall heat transfer and pressure drop. Moreover, the square pin results in a better heat transfer enhancement than the diamond pin, and subsequently than the circular pin. Finally, taking account of the lateral-flow rate and the flow Reynolds number, the work develops correlations of the endwall-averaged heat transfer with three different pin shapes.

scholarly journals Subsurface Lateral Flow in Texture-Contrast (Duplex) Soils and Catchments with Shallow Bedrock

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Marcus A. Hardie ◽  
Richard B. Doyle ◽  
William E. Cotching ◽  
Shaun Lisson
Keyword(s):  
Preferential Flow ◽  
Soil Surface ◽  
Field Studies ◽  
Lateral Flow ◽  
Review Of Literature ◽  
Antecedent Soil Moisture ◽  
Process Understanding ◽  
Subsurface Lateral Flow ◽  
Flow Through ◽  
Texture Contrast

Development-perched watertables and subsurface lateral flows in texture-contrast soils (duplex) are commonly believed to occur as a consequence of the hydraulic discontinuity between the A and B soil horizons. However, in catchments containing shallow bedrock, subsurface lateral flows result from a combination of preferential flow from the soil surface to the soil—bedrock interface, undulations in the bedrock topography, lateral flow through macropore networks at the soil—bedrock interface, and the influence of antecedent soil moisture on macropore connectivity. Review of literature indicates that some of these processes may also be involved in the development of subsurface lateral flow in texture contrast soils. However, the extent to which these mechanisms can be applied to texture contrast soils requires further field studies. Improved process understanding is required for modelling subsurface lateral flows in order to improve the management of waterlogging, drainage, salinity, and offsite agrochemicals movement.

Disposable lateral flow-through strip for smartphone-camera to quantitatively detect alkaline phosphatase activity in milk

2015 ◽  
Vol 69 ◽  
pp. 307-315 ◽  
Author(s):  
Ling Yu ◽  
ZhuanZhuan Shi ◽  
Can Fang ◽  
YuanYuan Zhang ◽  
YingShuai Liu ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Lateral Flow ◽  
Flow Through

Lateral flow through the sharp crested side rectangular weirs in open channels

2018 ◽  
Vol 59 ◽  
pp. 8-17 ◽  
Author(s):  
Ali Shariq ◽  
Ajmal Hussain ◽  
Mujib Ahmad Ansari
Keyword(s):  
Lateral Flow ◽  
Open Channels ◽  
Flow Through

Lateral-Flow Effect on Endwall Heat Transfer and Pressure Drop in a Pin-Fin Trapezoidal Duct of Various Pin Shapes

2000 ◽  
Author(s):  
Jenn-Jiang Hwang ◽  
Chau-Ching Lu
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Pressure Drop ◽  
Flow Rate ◽  
Lateral Flow ◽  
Transfer Enhancement ◽  
Pin Fin ◽  
Flow Reynolds Number ◽  
Outlet Flow ◽  
Flow Through

Effects of the lateral-flow ejection (0 ≦ ε ≦ 1.0), pin shapes (square, diamond and circular) and flow Reynolds number (6,000 ≦ Re ≦ 40,000) on the endwall heat transfer and pressure drop for turbulent flow through a pin-fin trapezoidal duct are studied experimentally. The trapezoidal duct are inserted with a staggered pin array of five rows and five columns, with the same spacings between the pins in streamwise and spanwise directions of Sx/d = Sy/d = 2.5. Three different-shaped pins of length from 2.5 < l/d < 4.6 span the distance between two endwalls of the trapezoidal duct. Results reveal that the pin-fin trapezoidal duct with a lateral-flow rate of ε = 0.3–0.4 has a local minimum endwall-averaged Nusselt number and Euler number for all pin shapes investigated. The trapezoidal duct of lateral outlet flow only (ε = 1.0) has the highest endwall heat transfer and pressure drop. Moreover, the square pin performs a better heat transfer enhancement than the diamond pin, and subsequently than the circular pin. Finally, taking account of the lateral-flow rate and the flow Reynolds number develops correlations of the endwall-averaged heat transfer for three different pin shapes.

scholarly journals Gold nanoparticle-based lateral flow kit for in vitro detection of malaria antibodies

2018 ◽  
Author(s):  
◽  
Christian Lungani Mthembu
Keyword(s):  
Test Line ◽  
Point Of Care ◽  
Three Dimensional ◽  
Lateral Flow ◽  
Igg Antibody ◽  
Diagnostic Kits ◽  
Test Kit ◽  
Malaria Antigen ◽  
And Performance

This study involves the development of three-dimensional dual lateral flow diagnostic assays. These assays were fabricated with quick response (QR) barcodes to ease the accessibility and transfer test data. The assays were designed to also improve the collection and transfer of survey from point-of-care facilities to centralized laboratories, thus, these would help to speed-up response to disease out-break. The study introduces the fabrication of two barcode based malaria diagnostic in the field of diagnostics. Two lateral flow kits were modified with two QR barcodes and three QR barcodes encoded with Google analytics codes for the detection and real-time tracking of malaria lateral flow which was designed to detect Plasmodium lactate dehydrogenase (pLDH). The fabrication of test kit was achieved by attaching two and three QR barcodes into two different test kits which were encoded with websites that were linked to Google analytics website as a tracking and performance monitor. Gold nanoparticles (AuNPs) were used as a substrate, where optical and structural properties were studied using UV/Visible spectroscopy, fluorescence spectroscopy, and transmission electron microscopy (TEM). The anti-mouse IgG antibody was used as a secondary antibody to act as control and the anti-(pLDH) was stripped on the test line. Phosphate buffer was used as a mobile phase solution. The antibody binding with pLDH antigen showed red test line indicating a positive test. Two diagnostic kits for rapid detection of pLDH were developed and validated for the detection of malaria antigen with lowest detectable recombinant concentration of 10 ng.mL-1. The diagnostic kits were incorporated with two and three optimally angled QR barcodes for identifying positive and negative. The second three QR barcode embedded test kit identified positive, negative and invalid using tracked website. These QR barcodes enabled massive results and tracking with precise location of the test through Google Analytics.

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