scholarly journals Test characteristics and potential impact of the urine LAM lateral flow assay in HIV-infected outpatients under investigation for TB and able to self-expectorate sputum for diagnostic testing

2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Jonny Peter ◽  
◽  
Grant Theron ◽  
Duncan Chanda ◽  
Petra Clowes ◽  
...  
Keyword(s):  
Diagnostic Testing ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Test Characteristics ◽  
Potential Impact

scholarly journals Microneedle-based skin patch for blood-free rapid diagnostic testing

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Xue Jiang ◽  
Peter B. Lillehoj
Keyword(s):  
Interstitial Fluid ◽  
Point Of Care ◽  
Diagnostic Testing ◽  
Protein Detection ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Detection Sensitivity ◽  
Sample Collection ◽  
Protein Biomarkers ◽  
Skin Patch

Abstract Rapid diagnostic tests are one of the most commonly used tests to detect and screen for infectious diseases in the developing world. While these tests are simple, inexpensive, and readily available, they rely on finger-prick blood sampling, which requires trained medical personnel, poses risks of infection, and can complicate cooperation in young children, asymptomatic individuals, and communities with blood taboos. Here, we report a novel microneedle-based skin patch for the rapid detection of protein biomarkers in dermal interstitial fluid. Sample collection is facilitated by a hydrophilic hollow microneedle array that autonomously extracts and transports interstitial fluid to an antibody-based lateral flow test strip via surface tension for colorimetric antigen detection. We employ a simple gold enhancement treatment to enhance the detection sensitivity of this colloidal gold-based lateral flow assay and elucidate the underlying mechanism of this enhancement mechanism through experimental investigation. For proof-of-concept, this device was used to detect Plasmodium falciparum histidine-rich protein 2, a biomarker for malaria infection, which could be detected at concentrations as low as 8 ng/mL. Each test can be completed in <20 min and requires no equipment. To the best of our knowledge, this work is the first demonstration of a microneedle-based lateral flow assay for rapid protein detection in dermal interstitial fluid. In addition to its simplicity, minimally invasive nature, and low cost, this diagnostic device can be readily adapted to detect other protein biomarkers in interstitial fluid, making it a promising tool for point-of-care testing.

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 Evaluation of a Cryptococcal Antigen Lateral Flow Assay and Cryptococcal Antigen Positivity at a Large Public Hospital in Atlanta, Georgia

2021 ◽  
Author(s):  
Kristin R V Harrington ◽  
Yun F (Wayne) Wang ◽  
Paulina A Rebolledo ◽  
Zhiyong Liu ◽  
Qianting Yang ◽  
...  
Keyword(s):  
Public Hospital ◽  
Clinical Care ◽  
Latex Agglutination ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Clinical Implications ◽  
Cryptococcal Antigen ◽  
Cryptococcal Disease ◽  
Percent Positivity ◽  
The U.S

Abstract Background Cryptococcus neoformans is a major cause of morbidity and mortality among HIV-infected persons worldwide, and there is scarce recent data on cryptococcal antigen (CrAg) positivity in the U.S. We sought to determine the frequency of cryptococcal disease and compare the performance of a CrAg lateral flow assay (LFA) versus latex agglutination (LA) test. Methods All patients from Grady Health System in Atlanta who had a serum or cerebrospinal fluid (CSF) sample sent for CrAg testing as part of clinical care from November 2017 – July 2018 were included. Percent positivity and test agreement were calculated. Results Among 467 patients, 557 diagnostic tests were performed; 413 on serum and 144 on CSF. Mean age was 44 years, most were male (69%) and had HIV (79%). Twenty-four (6.4%, CI95% = 4.1, 9.4) patients were serum CrAg positive, and eight (5.8%, CI95% = 2.6, 11.2) individuals tested positive for CSF CrAg. While overall agreement between the LA and LFA was substantial to high for CSF (κ= 0.71, CI95% = 0.51, 0.91) and serum (κ= 0.93, CI95% = 0.86, 1.00), respectively, there were important discrepancies. Five patients had false-positive CSF LA tests which affected clinical care, and four patients had discordant serum tests. Conclusions We found a moderately high proportion of cryptococcal disease and important discrepancies between the LA test and LFA. Clinical implications of these findings include accurate detection of serum CrAg and averting unnecessary treatment of meningitis with costly medications associated with high rates of adverse events.

scholarly journals Dual-signal lateral flow assay using vancomycin-modified nanotags for rapid and sensitive detection of Staphylococcus aureus

RSC Advances ◽  
2021 ◽  
Vol 11 (22) ◽  
pp. 13297-13303
Author(s):  
Shu Wang ◽  
Wanzhu Shen ◽  
Shuai Zheng ◽  
Zhigang Li ◽  
Chongwen Wang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Sensitive Detection

A colorimetric-fluorescent dual-signal lateral flow assay was proposed for the sensitive detection of S. aureus by using vancomycin-modified SiO2–Au-QD tags.

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