Detection of SARS-CoV-2 using machine learning-enabled paper-assisted ratiometric fluorescent sensors based on target-induced magnetic DNAzyme.

The development of an advanced analytical platform with regard to SARS-CoV-2 is crucial for public health. Herein, we present a machine learning platform based on paper-assisted ratiometric fluorescent sensors for highly sensitive detection of the SARS-CoV-2 RdRp gene. The assay involves target-induced rolling circle amplification to generate magnetic DNAzyme, which is then detectable using the paper-assisted ratiometric fluorescent sensor.

A functionalized Sup35NM nanofibril-assisted oriented antibody capture in lateral flow immunoassay for sensitive detection of dengue type II NS1.

Rapid and sensitive dengue non-structural protein 1 (NS1) detection assay is essential for the treatment of disease and currently releases high medical cost burdens. To address the limitations of conventional LFIA strips, we have developed an improved Sup35NM-Z-based LFIA that immobilizes antibodies on cellulose membranes in an orientated manner to increase the sensitivity of LFIA strips. A dual-functional Sup35NM nanofibril was fabricated by fusion with the antibody binding domain; resultant nanofibril from the amyloid Sup35NM was sprayed on the T-line to orientate the capture antibody and produces fluorescence signals.

Development, performance evaluation, and clinical application of a Rapid SARS-CoV-2 IgM and IgG Test Kit based on automated fluorescence immunoassay.

The ongoing coronavirus disease 2019 (COVID-19) epidemic has made a huge impact on health, economies, and societies all over the world. Although reverse transcription-polymerase chain reaction (RT-PCR)-based nucleic acid detection has been primarily used in the diagnosis of COVID-19, it is time-consuming with limited application scenarios and must be operated by qualified personnel. Antibody test, particularly point-of-care antibody testing, is a suitable complement to nucleic acid test as it provides rapid, portable, and cost-effective detection of infections.

Development of a lateral flow immunoassay of C-reactive protein detection based on red fluorescent nanoparticles.

We have developed a reliable and rapid immunoassay based on a facile synthesis of fluorescent nanoparticles integrated in immunochromatography technique to quantitatively detect C-reactive protein (CRP). The method is based on a sandwich immunoassay using the Nile-red doped nanoparticles/CRP monoclonal antibody conjugate. The method is simple and fast, with a detection limit of 0.

Rapid and Sensitive Detection of Cardiac Troponin I for Point-of-Care Tests Based on Red Fluorescent Microspheres.

A reliable lateral flow immunoassay (LFIA) based on a facile one-step synthesis of single microspheres in combining with immunochromatography technique was developed to establish a new point-of-care test (POCT) for the rapid and early detection of cardiac troponin I (cTnI), a kind of cardiac specific biomarker for acute myocardial infarction (AMI). The double layered microspheres with clear core-shell structures were produced using soap-free emulsion polymerization method with inexpensive compounds (styrene and acrylic acid). The synthetic process was simple, rapid and easy to control due to one-step synthesis without any complicated procedures.

Development of Monoclonal Antibodies against HIV-1 p24 Protein and Its Application in Colloidal Gold Immunochromatographic Assay for HIV-1 Detection.

Human immunodeficiency virus type 1 (HIV-1) p24 protein is the most abundant viral protein of HIV-1. This protein is secreted in blood serum at high levels during the early stages of HIV-1 infection, making it a biomarker for early diagnosis. In this study, a colloidal gold immunochromatographic assay (GICA) was established for detecting p24 protein using mouse monoclonal antibodies (mAbs).

Evaluation of a newly developed quantitative heart-type fatty acid binding protein assay based on fluorescence immunochromatography using specific monoclonal antibodies.

Objectives: To develop a rapid, sensitive and specific assay for quantification of serum heart-type fatty acid binding protein (H-FABP) based on immunofluorescence of specific monoclonal antibodies.

Design And Methods: We generated novel H-FABP-directed monoclonal antibodies by cloning of spleen cells of mice immunized with H-FABP. Epitopes were mapped and antigen affinity was assessed by surface plasmon resonance (SPR).

Development and performance evaluation of a novel immunofluorescence chromatographic assay for histidine-rich protein 2 of Plasmodium falciparum.

Background: The low sensitivity and specificity of Plasmodium falciparum diagnostic tests pose a serious health threat to people living in endemic areas. The objective of the study was to develop a rapid assay for the detection of histidine-rich protein 2 (HRP2) of P. falciparum in whole blood by immunofluorescence chromatographic technology.

Novel monoclonal antibodies against Plasmodium falciparum histidine-rich protein 2: development and application in rapid diagnostic tests of malaria in hyperendemic regions of China and Myanmar.

Background: Malaria presents a considerable threat to public health. Histidine-rich protein 2 (HRP 2) is the major protein released into human blood upon infection by Plasmodium falciparum. In this study, we aimed to evaluate the immunogenicity of HRP 2 exon II and the efficacy of novel monoclonal antibodies (mAbs) against HRP 2 for Point-of-Care Test (POCT).

Development of a fluorescent immnunochromatographic assay for the procalcitonin detection of clinical patients in China.

Background: Procalcitonin (PCT) has been recognized as a biomarker in severe inflammation, infection and sepsis. PCT detection in serum requires sensitive and specific antibodies. In this study, we generated monoclonal antibodies (mAbs) and developed fluorescent immunochromatographic assay for PCT detection.

Development of a monoclonal antibody-based indirect competitive immunosorbent assay for 4(5)-Methylimidazole detection in caramels.

In this study, an indirect competitive enzyme-linked immunoassay (ic-ELISA) based on monoclonal antibody for 4(5)-Methylimidazole (4-MI) detection was described. The artificial antigens were prepared by conjugating bovine serum albumin (BSA) or ovalbumin (OVA) with the hapten of 4-MI. And monoclonal antibody, evaluated by ic-ELISA, was obtained by immunizing BABL/c mice.

Comparative performance of aldolase and lactate dehydrogenase rapid diagnostic tests in Plasmodium vivax detection.

Background: Misdiagnosis of malaria by commercial rapid diagnostic tests (RDTs) is a major cause of concern in the diagnosis of malaria. This retrospective study was aimed at assessing the relative performance of four RDTs with emphasis on the detection of two Plasmodium vivax antigens: aldolase and lactate dehydrogenase (LDH).

Methods: Three commercially available Plasmodium LDH or aldolase antigen detection kits (One Step Malaria P.

Comparison of a new gold immunochromatographic assay for the rapid diagnosis of the novel influenza A (H7N9) virus with cell culture and a real-time reverse-transcription PCR assay.

We assessed a colloidal gold immunochromatographic assay (GICA) for rapid detection of influenza A (H7N9) and compared it with reverse-transcription-polymerase chain reaction (RT-PCR) and viral culture. Samples from 35 H7N9 infected patients were collected, including 45 throat swab samples, 56 sputum samples, and 39 feces samples. All samples were tested by GICA, viral culture, and RT-PCR.

Development of VHH antibodies against dengue virus type 2 NS1 and comparison with monoclonal antibodies for use in immunological diagnosis.

The possibility of using variable domain heavy-chain antibodies (VHH antibodies) as diagnostic tools for dengue virus (DENV) type 2 NS1 protein was investigated and compared with the use of conventional monoclonal antibodies. After successful expression of DENV type 2 NS1 protein, the genes of VHH antibodies against NS1 protein were biopanned from a non-immune llama library by phage display. VHH antibodies were then expressed and purified from Escherichia coli.

Development of rapid immunochromatographic test for hemagglutinin antigen of H7 subtype in patients infected with novel avian influenza A (H7N9) virus.

Background: Since human infection with the novel H7N9 avian influenza virus was identified in China in March 2013, the relatively high mortality rate and possibility of human-to-human transmission have highlighted the urgent need for sensitive and specific assays for diagnosis of H7N9 infection.

Methodology/principal Findings: We developed a rapid diagnostic test for the novel avian influenza A (H7N9) virus using anti-hemagglutinin (HA) monoclonal antibodies specifically targeting H7 in an immunochromatographic assay system. The assay limit of detection was 103.

Plasmodium vivax aldolase-specific monoclonal antibodies and its application in clinical diagnosis of malaria infections in China.

Background: Most rapid diagnostic tests (RDTs) currently used for malaria diagnosis cannot distinguish the various Plasmodium infections. The development of a Plasmodium vivax specific RDTs with high sensitivity to sufficiently differentiate the two most common Plasmodium infections would be very crucial for disease treatment and control.

Method: Plasmodium vivax aldolase gene (PvALDO) was amplified from the extracted genomic DNA and constructed into pET30a vector.

[Apoptosis of lens epithelial cell induced by curcumin and its mechanism].

Objective: To investigate the effects of natural drug curcumin (Cur) on apoptosis of lens epithelial cell (LEC) in vitro and its mechanism.

Methods: The bovine LEC were cultured with Cur, the ultrastructure changes were observed under transmission electron microscope (TEM), the DNA content and mitochondrial transmembrane potential (DeltaPsim) changes were studied by flow cytometry (FCM).

Results: The typical morphological changes of LEC apoptosis in Cur group detected by TEM included chromatin condensation and aggregation at the periphery of the nucleons and nuclear fragmentation.