Development and Clinical Evaluation of an Immunochromatography-Based Rapid Antigen Test (GenBody™ COVAG025) for COVID-19 Diagnosis.

Antigen tests for SARS-CoV-2 diagnosis are simpler and faster than their molecular counterparts. Clinical validation of such tests is a prerequisite before their field applications. We developed and clinically evaluated an immunochromatographic immunoassay, GenBody™ COVAG025, for the rapid detection of SARS-CoV-2 nucleocapsid (NP) antigen in two different clinical studies.

Clinical Evaluation of an Immunochromatographic-Based IgM/IgG Antibody Assay (GenBody™ COVI040) for Detection of Antibody Seroconversion in Patients with SARS-CoV-2 Infection.

There is a need for accurate diagnostic tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease (COVID-19). This study aimed to evaluate the diagnostic accuracy of an immunochromatography-based immunoglobulin G (IgG)/immunoglobulin M (IgM) antibody assay (GenBody™ COVI040) for detecting SARS-CoV-2 antibody seroconversion in COVID-19 patients. A total of 130 samples, serially collected from patients with confirmed COVID-19, and 100 negative control samples were tested for anti-SARS-CoV-2 IgM and IgG using the GenBody™ COVI040 assay following the South Korean Ministry of Food and Drug Safety guidelines on the review and approval of in vitro diagnostic devices for COVID-19.

Detection of Human Anti-Trypanosoma cruzi Antibody with Recombinant Fragmented Ribosomal P Protein.

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, and is endemic in many Latin American countries. Diagnosis is based on serologic testing and the WHO recommends two or more serological tests for confirmation. Acidic ribosomal P protein of T.

Development and Clinical Evaluation of a Rapid Diagnostic Test for Yellow Fever Non-Structural Protein 1.

A rapid diagnostic test (RDT) kit was developed to detect non-structural protein 1 (NS1) of yellow fever virus (YFV) using monoclonal antibody. NS1 protein was purified from the cultured YFV and used to immunize mice. Monoclonal antibody to NS1 was selected and conjugated with colloidal gold to produce the YFV NS1 RDT kit.

Identification of peptide based B-cell epitopes in Zika virus NS1.

Zika virus (ZIKV), a mosquito-borne flavivirus that has recently emerged globally, poses a major threat to public health. To control this emerging disease, accurate diagnostics are required for monitoring current ZIKV outbreaks. Owing to the high nucleotide sequence similarity and cross-reactivity of ZIKV with other members of the Flaviviridae family, discrimination from other flavivirus infections is often difficult in endemic areas.

Development of a Rapid Diagnostic Test Kit to Detect IgG/IgM Antibody against Zika Virus Using Monoclonal Antibodies to the Envelope and Non-structural Protein 1 of the Virus.

We developed a Rapid Diagnostic Test (RDT) kit for detecting IgG/IgM antibodies against Zika virus (ZIKV) using monoclonal antibodies to the envelope (E) and non-structural protein 1 (NS1) of ZIKV. These proteins were produced using baculovirus expression vector with Sf9 cells. Monoclonal antibodies J2G7 to NS1 and J5E1 to E protein were selected and conjugated with colloidal gold to produce the Zika IgG/IgM RDT kit (Zika RDT).

Seroprevalence of Toxoplasmosis Detected by RDT in Residents near the DMZ (demilitarized zone) of Cheorwon-gun, Gangwon-do, Korea.

Seroprevalence of Toxoplasma gondii infection among the residents of Cheorwon-gun, Gangwon-do, Korea, which partly includes the demilitarized zone (DMZ), were surveyed for 4 years and evaluated by RDT using recombinant fragment of major surface antigen (SAG1A). Sera from 1336, 583, 526, and 583 adult residents were collected on a yearly basis from 2010 to 2013, respectively. The total positive seroprevalence was 19.

Improvement of a rapid diagnostic application of monoclonal antibodies against avian influenza H7 subtype virus using Europium nanoparticles.

The development of a sensitive and rapid diagnostic test is needed for early detection of avian influenza (AI) H7 subtype. In this study, novel monoclonal antibodies (mAbs) against influenza A H7N9 recombinant hemagglutinin (rHA)1 were developed and applied to a Europium nanoparticle-based rapid fluorescent immunochromatographic strip test (FICT) to improve the sensitivity of the rapid diagnostic system. Two antibodies (2F4 and 6D7) exhibited H7 subtype specificity in a dot-FICT assay by optimization of the conjugate and the pH of the lysis buffer.

Seroprevalence of Toxoplasmosis with ELISA and Rapid Diagnostic Test among Residents in Gyodong-do, Inchon city, Korea: A Four-Year Follow-up.

ELISA has been used for the diagnosis of toxoplasmosis, but it is being gradually replaced by a rapid diagnostic test (RDT). We compared and analyzed ELISA and RDT results using the sera collected during 4 consecutive years from residents of Gyodong-do (Island), Incheon-city, Korea. Sera from 921, 993, 940, and 838 adult residents were collected on a yearly basis (2010-2013).

Rapid Detection of Avian Influenza Virus by Fluorescent Diagnostic Assay using an Epitope-Derived Peptide.

Currently, the point of care testing (POCT) is not fully developed for subtype-specific avian influenza virus detection. In this study, an H5N1 hemaglutinin 1 (HA1) epitope (P0: KPNDAINF) and three modified peptides (P1: KPNTAINF, P2: KPNGAINF, P3: KPNDAINDAINF) were evaluated as POCT elements for rapid detection of avian influenza virus. Based on modeling predictions by Autodock Vina, binding affinity varied depending on alteration of one amino acid in these peptides.

Rapid detection of avian influenza A virus by immunochromatographic test using a novel fluorescent dye.

Sensitive and rapid diagnostic systems for avian influenza (AI) virus are required to screen large numbers of samples during a disease outbreak and to prevent the spread of infection. In this study, we employed a novel fluorescent dye for the rapid and sensitive recognition of AI virus. The styrylpyridine phosphor derivative was synthesized by adding allyl bromide as a stable linker and covalently immobilizing it on latex beads with antibodies generating the unique Red dye 53-based fluorescent probe.

A Novel Malaria Pf/Pv Ab Rapid Diagnostic Test Using a Differential Diagnostic Marker Identified by Network Biology.

Rapid diagnostic tests (RDTs) can detect anti-malaria antibodies in human blood. As they can detect parasite infection at the low parasite density, they are useful in endemic areas where light infection and/or re-infection of parasites are common. Thus, malaria antibody tests can be used for screening bloods in blood banks to prevent transfusion-transmitted malaria (TTM), an emerging problem in malaria endemic areas.

Western Blot Detection of Human Anti-Chikungunya Virus Antibody with Recombinant Envelope 2 Protein.

Chikungunya virus (CHIKV), a tropical pathogen, has re-emerged and has massive outbreaks abruptly all over the world. Containing many dominant epitopes, the envelope E2 protein of CHIKV has been explored for the vaccination or diagnosis. In the present study, the antigenicity of a recombinant expressed intrinsically disorder domain (IUD) of E2 was tested for the detection of the antibody against CHIKV through western blot method.

Enhanced performance of an innovative dengue IgG/IgM rapid diagnostic test using an anti-dengue EDI monoclonal antibody and dengue virus antigen.

High levels of anti-dengue IgM or IgG can be detected using numerous rapid diagnostic tests (RDTs). However, the sensitivity and specificity of these tests are reduced by changes in envelope glycoprotein antigenicity that inevitably occur in limited expression systems. A novel RDT was designed to enhance diagnostic sensitivity.

Development and clinical evaluation of a highly accurate dengue NS1 rapid test: from the preparation of a soluble NS1 antigen to the construction of an RDT.

Early diagnosis of dengue virus (DENV) is important. There are numerous products on the market claiming to detect DENV NS1, but these are not always reliable. In this study, a highly sensitive and accurate rapid diagnostic test (RDT) was developed using anti-dengue NS1 monoclonal antibodies.

Clinical diagnosis of early dengue infection by novel one-step multiplex real-time RT-PCR targeting NS1 gene.

Background: Dengue is a mosquito-borne disease that causes a public health problem in tropical and subtropical countries. Current immunological diagnostics based on IgM and/or nonstructural protein 1 (NS1) antigen are limited for acute dengue infection due to low sensitivity and accuracy.

Objectives: This study aimed to develop a one-step multiplex real-time RT-PCR assay showing higher sensitivity and accuracy than previous approaches.

Evaluation of the accuracy of the EasyTest™ malaria Pf/Pan Ag, a rapid diagnostic test, in Uganda.

In recent years, rapid diagnostic tests (RDTs) have been widely used for malaria detection, primarily because of their simple operation, fast results, and straightforward interpretation. The Asan EasyTest™ Malaria Pf/Pan Ag is one of the most commonly used malaria RDTs in several countries, including Korea and India. In this study, we tested the diagnostic performance of this RDT in Uganda to evaluate its usefulness for field diagnosis of malaria in this country.

Rapid and quantitative detection of zoonotic influenza A virus infection utilizing coumarin-derived dendrimer-based fluorescent immunochromatographic strip test (FICT).

Great efforts have been made to develop robust signal-generating fluorescence materials which will help in improving the rapid diagnostic test (RDT) in terms of sensitivity and quantification. In this study, we developed coumarin-derived dendrimer-based fluorescent immunochromatographic strip test (FICT) assay with enhanced sensitivity as a quantitative diagnostic tool in typical RDT environments. The accuracy of the proposed FICT was compared with that of dot blot immunoassay techniques and conventional RDTs.

Probability of antibody formation against circumsporozoite protein of Plasmodium vivax among Korean malaria patients.

To evaluate the seroprevalence against circumsporozoite protein (CSP) of Plasmodium vivax in sera of Korean patients, the central repeating domain (CRD) of CSP was cloned and analyzed. From the genomic DNA of patient's blood, 2 kinds of CSPs were identified to belong to a VK210 type, which is the dominant repeating of GDRA(D/A)GQPA, and named as PvCSPA and PvCSPB. Recombinantly expressed his-tagged PvCSPA or PvCSPB in Escherichia coli reacted well against sera of patients in western blot, with the detecting rate of 47.

First characterization of Plasmodium vivax liver stage antigen (PvLSA) using synthetic peptides.

Background: Plasmodium vivax is the most widespread human malaria in tropical and subtropical countries, including the Republic of Korea. Vivax malaria is characterized by hypnozoite relapse and long latency infection by the retained liver stage of P. vivax, and somewhat surprisingly, little is known of the liver stage antigens of this parasite.

A rapid diagnostic test for toxoplasmosis using recombinant antigenic N-terminal half of SAG1 linked with intrinsically unstructured domain of gra2 protein.

Toxoplasma gondii is an apicomplexan parasite with a broad host range of most warm-blooded mammals including humans, of which one-thirds of the human population has been infected worldwide which can cause congenital defects, abortion, and neonatal complications. Here, we developed a rapid diagnostic test (RDT) for T. gondii infection.