8-hydroxy-2'-deoxyguanosine (8-OHdG) is a sensitive and stable biomarker for evaluating DNA oxidative damage. A rapid and sensitive colloidal gold immunochromatographic strip was developed for 8-OHdG detection by a competitive method. The sample pad (glass cellulose film), bonding pad (glass cellulose film), nitrocellulose film and absorbent pad were pasted on the polyvinyl chloride (PVC) base plate to construct the test strip. Colloidal gold (AuNPs) was prepared by the reduction of chloroauric acid with sodium citrate. 8-OHdG antibody (Ab) was coated on the outer layer of AuNPs to form Ab@AuNPs as a probe. Bovine serum albumin (BSA) and 8-OHdG were conjugated with carbodiimide hydrochloride to prepare an artificial antigen, which was used as the coating antigen of detection line. Goat anti mouse polyclonal antibody IgG was used as the coating antibody of control line. The experimental parameters were optimized including the type of nitrocellulose membrane, the formula of loading solution, and the spraying amount of gold labeled antibody. The results showed that the appropriate nitrocellulose membrane was CN 95. The optimal loading solution included BSA (1%), Tween-20 (3%), sucrose (3%) and NaCl (0.9%). The optimal spraying amount of gold labeled antibody was 4 μL. 8-OHdG can be detected by the strip under visible light, and the level of 8-OHdG in urine can be preliminarily determined by comparing the color intensity of T line and C line. The 8-OHdG concentration in urine was further calculated by the gray value of T line and the threshold of detection was 2.55 μg/L. This colloidal gold immunochromatographic strip is simple, rapid and specific for detecting 8-OHdG in human urine to preliminarily evaluate the human status.
8-Hydroxy-2'-Deoxyguanosine ; Animals ; Antibodies, Monoclonal ; Gold ; Gold Colloid/chemistry* ; Metal Nanoparticles ; Mice ; Sensitivity and Specificity

Brucella ; Brucellosis/diagnosis* ; Chromatography, Affinity ; Gold Colloid ; Humans

Colloidal gold immunochromatographic strip is a fast, sensitive and accurate solid-phase labeling detection technology, which has the advantages of low price, easy operation, rapid detection and high specificity, with the potential to qualitatively detect the relevant viruses in a short time with desired sensitivity and accuracy. It effectively addresses the disadvantages of long detection time, equipment inconvenience and professionalism requirement of the traditional detection methods used in the medical, veterinary, animal, plant virus detection, pesticide residue detection and other areas. Presently, the technology has been applied in the detection of bacterial diseases, viral diseases and prevention of extensive spread of infectious diseases, and has sufficient room for further development. This review summarizes the application of colloidal gold immunochromatography strip for biological virus detection, followed by prospecting future perspectives.
Animals ; Antibodies, Monoclonal/chemistry* ; Chromatography, Affinity ; Gold Colloid/chemistry* ; Pesticide Residues ; Sensitivity and Specificity

OBJECTIVE: To prepare monoclonal antibody against cotinine (COT) and to establish immunoassay for detecting COT in human urinary samples. METHODS: BALB/c mice were immunized with synthesized cotinine-bovine serum albumin (COT-BSA) to screen monoclonal antibody with technique of cell fusion. The monoclonal antibody was used for the indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and colloidal gold immunochromatographic strip assay for the detection of COT in human urine. RESULTS: The monoclonal antibody against COT was identified by ic-ELISA with a 50%inhibitive concentration (IC CONCLUSIONS The ic-ELISA and colloidal gold immunochromatographic strip assay using the prepared monoclonal antibody against COT have been proved to be reliable for the rapid detection of COT in human urines, which may be used for monitoring of environmental tobacco smoke.
Animals ; Antibodies, Monoclonal ; Cotinine/urine* ; Enzyme-Linked Immunosorbent Assay ; Gold Colloid ; Humans ; Mice ; Mice, Inbred BALB C ; Urinalysis/methods*

Antibodies, Viral ; blood ; Betacoronavirus ; immunology ; Coronavirus Infections ; diagnosis ; Gold Colloid ; chemistry ; Humans ; Immunoassay ; methods ; Immunoglobulin G ; blood ; Immunoglobulin M ; blood ; Pandemics ; Pneumonia, Viral ; diagnosis ; Reagent Kits, Diagnostic

This paper introduces a kind of immune colloidal gold detector instrument from the aspects of machinery,hardware and software.The instrument first collects one image through a CMOS sensor and then analyzes the image with image processing algorithm on Linux platform.Firstly,the instrument sets and stores the parameters separately for each test item,and then calls the saved item parameters when testing the item sample.So,the instrument can be used in a variety of fields and items.In this paper,a quantitative experimental test on C-reactive protein sample was performed,and the results indicate the coefficient of determination what denoted equal to 0.99,and the repeatability is greater than 93%.
Algorithms ; Gold Colloid ; Image Processing, Computer-Assisted ; instrumentation

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. The YFV RDTs were evaluated for sensitivity and specificity using positive and negative samples of monkeys from Brazil and negative human blood samples from Korea. Among monoclonal antibodies, clones 3A11 and 3B7 proved most sensitive, and used for YFV RDT kit. Diagnostic accuracy of YFV RDT was fairly high; Sensitivity was 0.0% and specificity was 100% against Dengue viruses type 2 and 3, Zika, Chikungunya and Mayaro viruses. This YFV RDT kit could be employed as a test of choice for point-of-care diagnosis and large scale surveys of YFV infection under clinical or field conditions in endemic areas and on the globe.
Animals ; Antibodies, Monoclonal ; Brazil ; Clone Cells ; Dengue Virus ; Diagnosis ; Diagnostic Tests, Routine ; Gold Colloid ; Haplorhini ; Humans ; Korea ; Mice ; Point-of-Care Systems ; Sensitivity and Specificity ; Yellow fever virus ; Yellow Fever

To establish a novel colloidal gold immunochromatography assay (GICA) for rapid, sensitive and accurate detection of Haemophilus influenzae infection by using the outer membrane protein P6 as detection target. First, the linear antigen epitope located in the extracellular domain of the P6 protein (GenBank accession number: AGH02799) was predicted by bioinformatics analysis. The region (62-75 aa of the protein) with strong antigen specificity was chosen and synthesized. Two rabbits were then immunized by the polypeptides (14 aa) for production of polyclonal antibodies. Then, the recombinant P6 proteins were also obtained to produce polyclonal antibodies. Finally, based on the two antibodies, a novel colloidal GICA for detection of Haemophilus influenzae infection was established and the specificity, sensitivity, repeatability and stability of this method were evaluated. At the same time, the method was tested in clinical simulation, and the plate culture method was used to verify its accuracy. The test strip for Haemophilus influenzae infection was successfully prepared. The detection limit of the test strip was as low as 1×105 CFU/mL and the whole process can be completed within 15 minutes. The strip specifically recognized Haemophilus influenzae and did not react with nine of other common respiratory pathogens such as Streptococcus pneumoniae, Moraxella catarrhalis, Mycoplasma pneumonia, and Legionella pneumophila. And the strips could be stored at 25 °C for at least 6 months without losing sensitivity or specificity. The coincidence rate between the results of 200 clinical samples and the plate culture method was 90.5%. Haemophilus influenzae protein P6, which possessed a high degree of surface antigen accessibility and antigencity, could be used as a marker for Haemophilus influenzae detection. The immunochromatographic colloidal gold test strip which bears the features of rapidity, convenience and sensitivity provides a unique tool for the on-site surveillance and diagnosis of Haemophilus influenzae infection in clinical test.
Animals ; Chromatography, Affinity ; instrumentation ; Diagnostic Tests, Routine ; standards ; Gold Colloid ; chemistry ; Haemophilus Infections ; diagnosis ; Haemophilus influenzae ; Humans ; Limit of Detection ; Rabbits ; Sensitivity and Specificity

Rice stripe virus (RSV) causes dramatic losses in rice production worldwide. In this study, two monoclonal antibodies (MAbs) 16E6 and 11C1 against RSV and a colloidal gold-based immunochromatographic strip were developed for specific, sensitive, and rapid detection of RSV in rice plant and planthopper samples. The MAb 16E6 was conjugated with colloidal gold and the MAb 11C1 was coated on the test line of the nitrocellulose membrane of the test strip. The specificity of the test strip was confirmed by a positive reaction to RSV-infected rice plants and small brown planthopper (SBPH), and negative reactions to five other rice viruses, healthy rice plants, four other vectors of five rice viruses, and non-viruliferous SBPH. Sensitivity analyses showed that the test strip could detect the virus in RSV-infected rice plant tissue crude extracts diluted to 1:20 480 (w/v, g/mL), and in individual viruliferous SBPH homogenate diluted to 1:2560 (individual SPBH/μL). The validity of the developed strip was further confirmed by tests using field-collected rice and SBPH samples. This newly developed test strip is a low-cost, fast, and easy-to-use tool for on-site detection of RSV infection during field epidemiological studies and paddy field surveys, and thus can benefit decision-making for RSV management in the field.
Antibodies, Monoclonal/chemistry* ; China ; Chromatography, Affinity/methods* ; Collodion/chemistry* ; Colloids/chemistry* ; Gold Colloid/chemistry* ; Materials Testing ; Membranes, Artificial ; Oryza/virology* ; Plant Diseases/virology* ; Reproducibility of Results ; Sensitivity and Specificity ; Species Specificity ; Tenuivirus/isolation & purification*

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). Comparisons with ELISA, plaque reduction neutralization test (PRNT), and PCR were done to investigate the analytical sensitivity of Zika RDT, which resulted in 100% identical results. Sensitivity and specificity of Zika RDT in a field test was determined using positive and negative samples from Brazil and Korea. The diagnostic accuracy of Zika RDT was fairly high; sensitivity and specificity for IgG was 99.0 and 99.3%, respectively, while for IgM it was 96.7 and 98.7%, respectively. Cross reaction with dengue virus was evaluated using anti-Dengue Mixed Titer Performance Panel (PVD201), in which the Zika RDT showed cross-reactions with DENV in 16.7% and 5.6% in IgG and IgM, respectively. Cross reactions were not observed with West Nile, yellow fever, and hepatitis C virus infected sera. Zika RDT kit is very simple to use, rapid to assay, and very sensitive, and highly specific. Therefore, it would serve as a choice of method for point-of-care diagnosis and large scale surveys of ZIKV infection under clinical or field conditions worldwide in endemic areas.
Antibodies ; Antibodies, Monoclonal ; Baculoviridae ; Brazil ; Cross Reactions ; Dengue Virus ; Diagnosis ; Diagnostic Tests, Routine ; Enzyme-Linked Immunosorbent Assay ; Flavivirus ; Gold Colloid ; Hepacivirus ; Immunoglobulin G ; Immunoglobulin M ; Korea ; Methods ; Neutralization Tests ; Point-of-Care Systems ; Polymerase Chain Reaction ; Reagent Kits, Diagnostic ; Sensitivity and Specificity ; Sf9 Cells ; Yellow Fever ; Zika Virus