A Time-Resolved-Fluorescence Lateral Flow Assay for Rapid Detection of Cholyglycine Acid for the Diagnosis of Liver Diseases

Liver disease is a great danger to human health. The determination of blood level of Cholyglycine acid (CG) is a vital biomarker for the assessment of liver function in clinic, which is contribute to the diagnosis of liver diseases. Thus, establishing accuracy, rapid and convenient method for the detection of glycolic acid is of great significance. In this study, a time-resolved-fluorescence (TRF) lateral flow assay for rapid detection of CG was development. The analytical detection limit (mean of zero-2 SD) was 0.06 μg/mL The method showed good linearity in the range of 0.2–40 g/mL and was not affected by biomolecules with similar structure to CG. The analytical mean recovery of control was between 90–110% and the imprecision of intra- and inter-assay of CVs was less than 10%. No significant matrix effect was observed in saline, serum, plasma or whole blood. A good correlation was found with the homogeneous enzyme immunoassay (HEIA) assay (slopes 1.0463, y-intercepts 0.2721 μg/mL, R = 0.989, n = 50, P < 0.001). The CG TRF analysis could provide reproducible and quantitative information about the state of liver in a few minutes, which is suitable for the detection of liver diseases in point-of-care-testing (POCT) conditions.

Download Full-text

Europium nanosphere-based fluorescence strip sensor for ultrasensitive and quantitative determination of fumonisin B1

Analytical Methods ◽

10.1039/d0ay01734e ◽

2020 ◽

Vol 12 (43) ◽

pp. 5229-5235

Author(s):

Lingling Guo ◽

Zhongxing Wang ◽

Xinxin Xu ◽

Liguang Xu ◽

Hua Kuang ◽

...

Keyword(s):

Quantitative Determination ◽

Rapid Detection ◽

Detection Method ◽

Fumonisin B1 ◽

Immunochromatographic Assay ◽

Time Resolved Fluorescence ◽

Time Resolved

The developed time-resolved fluorescence immunochromatographic assay can be widely applicable as an ultrasensitive, rapid detection method for FB1 in grains.

Download Full-text

A hemagglutination-based, semi-quantitative test for point-of-care determination of SARS-CoV-2 antibody levels

Journal of Clinical Microbiology ◽

10.1128/jcm.01186-21 ◽

2021 ◽

Author(s):

Robert L. Kruse ◽

Yuting Huang ◽

Alyssa Lee ◽

Xianming Zhu ◽

Ruchee Shrestha ◽

...

Keyword(s):

Point Of Care ◽

Neutralizing Antibody ◽

Antibody Test ◽

Quantitative Information ◽

Elisa Test ◽

Lateral Flow ◽

Plasma Samples ◽

Hemagglutination Test ◽

Lateral Flow Assays

Serologic, point-of-care tests to detect antibodies against SARS-CoV-2 are an important tool in the COVID-19 pandemic. The majority of current point-of-care antibody tests developed for SARS-CoV-2 rely on lateral flow assays, but these do not offer quantitative information. To address this, we developed a novel antibody test leveraging hemagglutination, employing a dry card format currently used for typing ABO blood groups. 200 COVID-19 patient and 200 control plasma samples were reconstituted with O-negative RBCs to form whole blood and added to dried viral-antibody fusion protein, followed by a stirring step and a tilting step, 3-minute incubation, and a second tilting step. The sensitivity for the hemagglutination test, Euroimmun IgG ELISA test and RBD-based CoronaChek lateral flow assay was 87.0%, 86.5%, and 84.5%, respectively, using samples obtained from recovered COVID-19 individuals. Testing pre-pandemic samples, the hemagglutination test had a specificity of 95.5%, compared to 97.3% and 98.9% for the ELISA and CoronaChek, respectively. A distribution of agglutination strengths was observed in COVID-19 convalescent plasma samples, with the highest agglutination score (4) exhibiting significantly higher neutralizing antibody titers than weak positives (2) (p<0.0001). Strong agglutinations were observed within 1 minute of testing, and this shorter assay time also increased specificity to 98.5%. In conclusion, we developed a novel rapid, point-of-care RBC agglutination test for the detection of SARS-CoV-2 antibodies that can yield semi-quantitative information on neutralizing antibody titer in patients. The five-minute test may find use in determination of serostatus prior to vaccination, post-vaccination surveillance and travel screening.

Download Full-text

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

Journal of Clinical and Medical Research ◽

10.37191/mapsci-2582-4333-2(3)-032 ◽

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.

Download Full-text

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

Journal of Clinical and Medical Research ◽

10.37191/mapsci-2582-4333-2(2)-032 ◽

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.

Download Full-text