scholarly journals EDTA-K2 Improves the Detection Sensitivity of SARS-CoV-2 IgM and IgG Antibodies by Chelating Colloidal Gold in the Immunochromatographic Assay

2021 ◽  
Vol Volume 16 ◽  
pp. 715-724
Author(s):  
Xiumei Hu ◽  
Changmeng Wu ◽  
Bo Situ ◽  
Peifu Tian ◽  
Taixue An ◽  
...  
Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 365
Author(s):  
Fengli Liu ◽  
Yanxin Cao ◽  
Maokai Yan ◽  
Mengxu Sun ◽  
Qingshui Zhang ◽  
...  

Duck viral enteritis is a highly contagious and fatal disease of commercial waterfowl flocks. The disease occurs sporadically or epizootically in mainland China due to insufficient vaccinations. Early and rapid diagnosis is important for preventive intervention and the control of epizootic events in clinical settings. In this study, we generated two monoclonal antibodies (MAbs) that specifically recognized the duck enteritis virus (DEV) envelope glycoprotein B and tegument protein UL47, respectively. Using these MAbs, a colloidal gold-based immunochromatographic assay (ICA) was developed for the efficient detection of DEV antigens within 15 min. Our results showed that the detection limit of the developed ICA strip was 2.52 × 103 TCID50/mL for the virus infected cell culture suspension with no cross-reactivity with other pathogenic viruses commonly encountered in commercially raised waterfowl. Using samples from experimentally infected ducks, we demonstrated that the ICA detected the virus in cloacal swab samples on day three post-infection, demonstrating an 80% concordance with the PCR. For tissue homogenates from ducks succumbing to infection, the detection sensitivity was 100%. The efficient and specific detection by this ICA test provides a valuable, convenient, easy to use and rapid diagnostic tool for DVE under both laboratory and field conditions.


Author(s):  
Jie Xiang ◽  
Mingzhe Yan ◽  
Hongze Li ◽  
Ting Liu ◽  
Chenyao Lin ◽  
...  

AbstractBACKGROUNDIn December 2019, a novel coronavirus (SARS-CoV-2)–infected pneumonia (COVID-19) occurred in Wuhan, China. Travel-associated cases have also been reported in other countries. The number of cases has increased rapidly but laboratory diagnosis is limited.METHODSWe collect two groups of cases diagnosed with COVID-19 for experiments. One group collected 63 samples for Enzyme-linked immunosorbent assay (ELISA) IgG and IgM antibodies. The other group collected 91 plasma samples for colloidal gold-immunochromatographic assay (GICA).RESULTSThe sensitivity of the combined ELISA IgM and ELISA IgG detection was 55/63 ( 87.3%), The sensitivity of the combined GICA IgM and GICA IgG detection was 75/91 ( 82.4%), Both methods are negative for healthy controls, specificity of 100%. There is no significant difference between the sensitivity of between ELISA and GICA (IgM+ IgG).CONCLUSIONSELISA and GICA for specific IgM and IgG antibodies are conventional serological assays, they are simple, fast, and safe, the results can be used for clinical reference, and the huge clinical diagnosis and treatment pressure can be greatly relieved.


Author(s):  
George H. Herbener ◽  
Antonio Nanci ◽  
Moise Bendayan

Protein A-gold immunocytochemistry is a two-step, post-embedding labeling procedure which may be applied to tissue sections to localize intra- and extracellular proteins. The key requisite for immunocytochemistry is the availability of the appropriate antibody to react in an immune response with the antigenic sites on the protein of interest. During the second step, protein A-gold complex is reacted with the antibody. This is a non- specific reaction in that protein A will combine with most IgG antibodies. The ‘label’ visualized in the electron microscope is colloidal gold. Since labeling is restricted to the surface of the tissue section and since colloidal gold is particulate, labeling density, i.e., the number of gold particles per unit area of tissue section, may be quantitated with ease and accuracy.


2022 ◽  
Vol 12 ◽  
Author(s):  
Zhen Zhu ◽  
Guanggang Qu ◽  
Changjiang Wang ◽  
Lei Wang ◽  
Jige Du ◽  
...  

Mycoplasma capricolum subsp. capripneumoniae (Mccp) is the cause of contagious caprine pleuropneumonia (CCPP), which is a highly significant respiratory disease in goats leading to significant economic losses in Africa and Asia. Currently available procedures for the diagnosis of CCPP have some limitations in sensitivity, specificity, operation time, requirement of sophisticated equipment or skilled personnel, and cost. In this study, we developed a rapid, sensitive, and specific colloidal gold-based immunochromatographic assay (GICA) strip for the efficient on-site detection of antibodies against Mccp in the serum within 10 min. For the preparation of this colloidal GICA strip, recombinant P20 protein, the membrane protein of Mccp, was expressed by Escherichia coli prokaryotic expression system after purification was used as the binding antigen in the test. The rabbit anti-goat immunoglobulin G labeled with the colloidal gold was used as the detection probe, whereas the goat anti-rabbit immunoglobulin G was coated on the nitrocellulose membrane as the control line. The concentration of the coating antibody was optimized, and the effectiveness of this colloidal GICA strip was evaluated. Our results proved that the detection limit of the test strip was up to 1:64 dilutions for the Mccp antibody-positive serum samples with no cross-reactivity with other pathogens commonly infecting small ruminants,including goat pox virus, peste des petits ruminants virus, foot-and-mouth disease virus type A, or other mycoplasmas. Moreover, the colloidal GICA strip was more sensitive and specific than the indirect hemagglutination assay for the detection of Mccp antibodies. The 106 clinical serum samples were detected by the colloidal GICA strip compared with the complement fixation test, demonstrating an 87.74% concordance with the complement fixation test. This novel colloidal GICA strip would be an effective tool for the cost-effective and rapid diagnosis of CCPP in the field.


2015 ◽  
Vol 51 (8) ◽  
pp. 834-839 ◽  
Author(s):  
D. V. Sotnikov ◽  
A. V. Zherdev ◽  
V. G. Avdienko ◽  
B. B. Dzantiev

2018 ◽  
Vol 9 ◽  
Author(s):  
Xianglong Yu ◽  
Lei Wei ◽  
Hao Chen ◽  
Xiaoyu Niu ◽  
Yanguo Dou ◽  
...  

2018 ◽  
Vol 10 (37) ◽  
pp. 4505-4510 ◽  
Author(s):  
Namei Liu ◽  
Keyu Xing ◽  
Chun Wang ◽  
Ganggang Zhang ◽  
Meifang Yuan ◽  
...  

A colloidal gold immunochromatographic assay (CG-ICA) was developed to detect sulfamethazine (SM2) residues in five kinds of meat: namely, chicken, pork, shrimp, beef, and fish.


Sign in / Sign up

Export Citation Format

Share Document