scholarly journals Improved sensitivity and limit-of-detection of lateral flow devices using spatial constrictions of the flow-path

2018 ◽  
Vol 113 ◽  
pp. 95-100 ◽  
Author(s):  
Ioannis N. Katis ◽  
Peijun J.W. He ◽  
Robert W. Eason ◽  
Collin L. Sones
Keyword(s):  
Limit Of Detection ◽  
Flow Path ◽  
Lateral Flow ◽  
Flow Devices

Feasibility of Immunodiagnostic Devices for the Detection of Ricin, Amanitin, and T-2 Toxin in Food

2005 ◽  
Vol 68 (6) ◽  
pp. 1294-1301 ◽  
Author(s):  
ERIC A. E. GARBER ◽  
ROBERT M. EPPLEY ◽  
MICHAEL E. STACK ◽  
MICHAEL A. McLAUGHLIN ◽  
DOUGLAS L. PARK
Keyword(s):  
High Throughput Screening ◽  
Limit Of Detection ◽  
Extraction Methods ◽  
Food Samples ◽  
Lateral Flow ◽  
Health Concern ◽  
High Background ◽  
Baked Goods ◽  
Simple Extraction ◽  
Flow Devices

Qualitative and quantitative comparisons were conducted of commercially available immunodiagnostic devices for the detection of three select agents with oral LD50 values ≥0.1 mg/kg of body weight. Ricin (oral LD50 > 1 mg/kg), amanitin (oral LD50 approximately 0.1 mg/kg), and T-2 toxin (oral LD50 > 1 mg/kg) were spiked into beverages, produce, dairy, and baked goods and assayed using commercially available enzyme-linked immunosorbent assays (ELISAs) and lateral flow devices. In all cases, the commercial diagnostic kits successfully detected all three select agents at concentrations below what might be a health concern. The considerable difference between the limit of detection of the immunodiagnostic devices employed (typically ≤0.020 μg/g) and the amount of the select agent necessary to pose a health threat in a single serving of food facilitated the design of protocols for the high throughput screening of food samples. These protocols entailed simple extraction methods followed by sample dilution. Lateral flow devices and sandwich ELISAs for the detection of ricin had no significant background problems due to the food matrices. Competitive ELISAs, which typically have unacceptably high background reactions with food samples, successfully detected amanitin and T-2 toxin.

A Point of Care Lateral Flow Assay for Rapid and Colorimetric Detection of Interleukin 6 and Perspectives in Bedside Diagnostics

2020 ◽  
Author(s):  
Carla Eiras
Keyword(s):  
Interleukin 6 ◽  
Limit Of Detection ◽  
Inflammatory Diseases ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Aggregation Assay ◽  
Before And After ◽  
Bedside Diagnosis

Interleukin-6 (IL-6) is a multifunctional cytokine and high bloodstream levels of which have been associated with severe inflammatory diseases, such as dengue fever, sepsis, various cancers, and visceral leishmaniasis (VL). Rapid tests for the quantification of IL-6 would be of great assistance for the bedside diagnosis and treatment of diseases such as VL. We have developed a lateral flow assay (LFA) for rapid and colorimetric IL-6 detection, consisting of anti-IL-6 antibodies conjugated to gold nanoparticles (AuNPs). The optimal concentration of anti-IL-6 used in the conjugate was determined to be 800.0 μg/mL, based on an aggregation assay using LFA. A linear relationship between IL-6 standard concentration and color intensity was observed after 20 min, with a linear range between 1.25 ng/mL and 9,000 ng/mL. The limit of detection for this method was estimated a t0.38 ng/mL. The concentration of IL-6 in five patients with severe VL was measured using LFA, and the results were consistent with those obtained using the cytometric bead array (CBA) method. A thorough analysis of the LFA membranes’ surface morphology, before and after sample contact, was performed using atomic force microscopy (AFM).The prototype described here is still being tested and improved, but this LFA will undoubtedly be of great help in the clinical quantification of IL-6.

A Point of Care Lateral Flow Assay for Rapid and Colorimetric Detection of Interleukin 6 and Perspectives in Bedside Diagnostics

2020 ◽  
Author(s):  
Carla Eiras
Keyword(s):  
Interleukin 6 ◽  
Limit Of Detection ◽  
Inflammatory Diseases ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Aggregation Assay ◽  
Before And After ◽  
Bedside Diagnosis

Interleukin-6 (IL-6) is a multifunctional cytokine and high bloodstream levels of which have been associated with severe inflammatory diseases, such as dengue fever, sepsis, various cancers, and visceral leishmaniasis (VL). Rapid tests for the quantification of IL-6 would be of great assistance for the bedside diagnosis and treatment of diseases such as VL. We have developed a lateral flow assay (LFA) for rapid and colorimetric IL-6 detection, consisting of anti-IL-6 antibodies conjugated to gold nanoparticles (AuNPs). The optimal concentration of anti-IL-6 used in the conjugate was determined to be 800.0 μg/mL, based on an aggregation assay using LFA. A linear relationship between IL-6 standard concentration and color intensity was observed after 20 min, with a linear range between 1.25 ng/mL and 9,000 ng/mL. The limit of detection for this method was estimated at a t0.38 ng/mL. The concentration of IL-6 in five patients with severe VL was measured using LFA, and the results were consistent with those obtained using the cytometric bead array (CBA) method. A thorough analysis of the LFA membranes’ surface morphology, before and after sample contact, was performed using atomic force microscopy (AFM). The prototype described here is still being tested and improved, but this LFA will undoubtedly be of great help in the clinical quantification of IL-6.

scholarly journals Multi-Quantum Dots-Embedded Silica-Encapsulated Nanoparticle-Based Lateral Flow Assay for Highly Sensitive Exosome Detection

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 768
Author(s):  
Hyung-Mo Kim ◽  
Chiwoo Oh ◽  
Jaehyun An ◽  
Seungki Baek ◽  
Sungje Bock ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Limit Of Detection ◽  
Specific Binding ◽  
Calf Serum ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Uniform Size ◽  
Highly Sensitive ◽  
Wide Range ◽  
New Biomarkers

Exosomes are attracting attention as new biomarkers for monitoring the diagnosis and prognosis of certain diseases. Colorimetric-based lateral-flow assays have been previously used to detect exosomes, but these have the disadvantage of a high limit of detection. Here, we introduce a new technique to improve exosome detection. In our approach, highly bright multi-quantum dots embedded in silica-encapsulated nanoparticles (M–QD–SNs), which have uniform size and are brighter than single quantum dots, were applied to the lateral flow immunoassay method to sensitively detect exosomes. Anti-CD63 antibodies were introduced on the surface of the M–QD–SNs, and a lateral flow immunoassay with the M–QD–SNs was conducted to detect human foreskin fibroblast (HFF) exosomes. Exosome samples included a wide range of concentrations from 100 to 1000 exosomes/µL, and the detection limit of our newly designed system was 117.94 exosome/μL, which was 11 times lower than the previously reported limits. Additionally, exosomes were selectively detected relative to the negative controls, liposomes, and newborn calf serum, confirming that this method prevented non-specific binding. Thus, our study demonstrates that highly sensitive and quantitative exosome detection can be conducted quickly and accurately by using lateral immunochromatographic analysis with M–QD–SNs.

Lateral flow devices for nucleic acid analysis exploiting quantum dots as reporters

2015 ◽  
Vol 864 ◽  
pp. 48-54 ◽  
Author(s):  
Eleni A. Sapountzi ◽  
Sotirios S. Tragoulias ◽  
Despina P. Kalogianni ◽  
Penelope C. Ioannou ◽  
Theodore K. Christopoulos
Keyword(s):  
Quantum Dots ◽  
Nucleic Acid ◽  
Lateral Flow ◽  
Nucleic Acid Analysis ◽  
Flow Devices

scholarly journals Validation of Two Commercial Lateral Flow Devices for the Detection of Peanut Proteins in Cookies: Interlaboratory Study

2006 ◽  
Vol 89 (2) ◽  
pp. 462-468 ◽  
Author(s):  
Arjon J van Hengel ◽  
Claudia Capelletti ◽  
Marcel Brohee ◽  
Elke Anklam ◽  
M-C S Baumgartner ◽  
...  
Keyword(s):  
False Negative ◽  
Lateral Flow ◽  
Food Matrix ◽  
Negative Results ◽  
False Negative Results ◽  
Test Kit ◽  
Interlaboratory Validation ◽  
Peanut Proteins ◽  
Flow Devices ◽  
Positive Results

Abstract Results are reported for an interlaboratory validation study of 2 commercially available lateral flow devices (dipstick tests) designed to detect peanut residues in food matrixes. The test samples used in this study were cookies containing peanuts at 7 different concentrations in the range of 030 mg peanuts/kg food matrix. The test samples with sufficient and proven homogeneity were prepared in our laboratory. The analyses of the samples (5 times per level by each laboratory) were performed by 18 laboratories worldwide, which submitted a total of 1260 analytical results. One laboratory was found to be an outlier for one of the test kits. In general, both test kits performed well. However, some false-negative results were reported for all matrixes containing <21 mg peanuts/kg cookie. It must be stressed that the test kits were challenged beyond their cut-off limits (5 mg/kg, depending on the food matrix). One test kit showed fewer false-negative results, but it led to some false-positive results for the blank materials. The sensitivity of the dipstick tests approaches that achieved with enzyme-linked immunosorbent assays.

Development of a Smartphone Based Reader for the Quantitative Analysis of Lateral Flow Assays

2018 ◽  
Vol 941 ◽  
pp. 2522-2527
Author(s):  
Sylvio Schneider ◽  
Martina Selig ◽  
Verena Keil ◽  
Matthias Lehmann ◽  
Andreas H. Foitzik ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Medical Devices ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Thrombotic Event ◽  
Lateral Flow ◽  
Proof Of Concept ◽  
Lateral Flow Assays ◽  
Further Development ◽  
D Dimer

Smartphones are developing into all-purposes devices. In the present work, the employment/application of smartphones as medical devices in home care and point-of-care (POC) diagnostics are investigated in the analysis of Lateral Flow Assays (LFA). A smartphone-based LFA reader was developed for the quantitative analysis of D-Dimer – a biomarker indicating e.g. thrombotic event or danger of embolism.The proof-of-concept has been shown with multiple smartphones in establishing: (I) Optimal dimensions of the LFA cell of 72.11mm distance of smartphone to D-Dimer test leading to a coefficients of variances (CV) between 0.8% and 4.2%. (II) Inter-device investigations: CVs around 13.5%; a limit of detection (LOD) of 100ng/ml (DDU) D-Dimer. (III) Inter-smartphone investigations: CV about 16%, a limit of detection (LOD) at 66.4ng/ml (DDU). (IV) Calibrations: CV and LOD of three smartphones are comparable to the commercial available LFA reader. Further development to put the multiple smartphone-based LFA reader on the market.

Evaluation of rapid test kits for quantification of deoxynivalenol in naturally contaminated oats and wheat

2012 ◽  
Vol 5 (4) ◽  
pp. 339-350 ◽  
Author(s):  
H.U. Aamot ◽  
I.S. Hofgaard ◽  
G. Brodal ◽  
O. Elen ◽  
M. Jestoi ◽  
...  
Keyword(s):  
European Union ◽  
Rapid Test ◽  
Reference Method ◽  
Lateral Flow ◽  
First Report ◽  
Ms Analysis ◽  
Simultaneous Testing ◽  
Immunosorbent Assays ◽  
Flow Devices

The aim of this study was to evaluate the performance of rapid test kits for analysis of deoxynivalenol (DON), a mycotoxin commonly found in small-grain cereals. Concentrations of DON and its acetylated derivative 3-acetyldeoxynivalenol (3-ADON) were analysed in naturally contaminated wheat (n=56) and oats (n=81) using two enzyme-linked immunosorbent assays, i.e. Ridascreen® DON (‘Standard ELISA’) and Ridascreen® FAST DON (‘Fast ELISA’), and two lateral flow devices, i.e. Rida® QUICK DON (‘Quick LFD’) and Rosa® DON (‘Rosa LFD’). Analysis by the LC-MS/MS reference method showed a median DON + 3-ADON concentration of 1,168 μg/kg (90th percentile 3,264 μg/kg) in wheat and 2,250 μg/kg (90th percentile of 9,008 μg/kg) in oats. Rosa LFD offered the best reliability, achieving detection that was stable across toxin levels in both matrices. In addition, Rosa LFD had the highest accuracy (i.e. proportion of correct results) at a DON level of 1,250 μg/kg in wheat (0.83) and 8,000 μg/kg in oats (0.96). Standard ELISA achieved the highest accuracy at a DON level of 1,750 μg/kg in oats (0.85). Detection by Quick LFD in wheat and Fast ELISA in both wheat and oats differed significantly among toxin levels (P≤0.05), with recoveries outside European Union requirements (70-120%) in some cases. The correlation with results from LC-MS/MS analysis in oats was best for Rosa LFD (R2=0.79). In wheat, however the correlation was best for Fast ELISA (R2=0.81). Rosa LFD was regarded as well-suited for on-site detection. Standard ELISA allowed simultaneous testing of several samples and achieved detection that was stable across toxin levels in both matrices, making it a useful alternative in laboratories. To our knowledge, this is the first report describing the performance of rapid test kits for detection of DON in naturally contaminated oats.

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