scholarly journals Dye-Loaded Polymersome-Based Lateral Flow Assay: Rational Design of a COVID-19 Testing Platform by Repurposing SARS-CoV-2 Antibody Cocktail and Antigens Obtained from Positive Human Samples

ACS Sensors ◽  
2021 ◽  
Author(s):  
Faezeh Ghorbanizamani ◽  
Kerem Tok ◽  
Hichem Moulahoum ◽  
Duygu Harmanci ◽  
Simge Balaban Hanoglu ◽  
...  
2020 ◽  
Author(s):  
Brett Ragnesola ◽  
Daniel Jin ◽  
Chris C. Lamb ◽  
Beth H. Shaz ◽  
Christopher D. Hillyer ◽  
...  

Abstract Objective: COVID19 has caused a global and ongoing pandemic. The need for population seroconversion data is apparent to monitor and respond to the pandemic. Using a lateral flow assay (LFA) testing platform, the seropositivity in 63 New York Blood Center (NYBC)Convelescent Plasma (CP) donor samples were evaluated for the presence of COVID19 specific IgG and IgM.Results: CP donors showed diverse antibody result.Convalescent donor plasma contains SARS-CoV-2 specific antibodies. Weak antibody bands may identify low titer CP donors.LFA tests can identify antibody positive individuals that have recovered from COVID19. Confirming suspected cases using antibody detection could help inform the patient and the community as to the relative risk to future exposure and a better understanding of disease exposure.


Author(s):  
Carla Eiras

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.


Author(s):  
Carla Eiras

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.


Author(s):  
Kristin R V Harrington ◽  
Yun F (Wayne) Wang ◽  
Paulina A Rebolledo ◽  
Zhiyong Liu ◽  
Qianting Yang ◽  
...  

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.


RSC Advances ◽  
2021 ◽  
Vol 11 (22) ◽  
pp. 13297-13303
Author(s):  
Shu Wang ◽  
Wanzhu Shen ◽  
Shuai Zheng ◽  
Zhigang Li ◽  
Chongwen Wang ◽  
...  

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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