Gold Immunochromatographic Test Strip Research Articles

A Modified Quantum Dot-Based Dot Blot Assay for Rapid Detection of Fish Pathogen Vibrio anguillarum.

Vibrio anguillarum, a devastating pathogen causing vibriosis among marine fish, is prevailing in worldwide fishery industries and accounts for grievous economic losses. Therefore, a rapid on-site detection and diagnostic technique for this pathogen is in urgent need. In this study, two mouse monoclonal antibodies (MAbs) against V. anguillarum, 6B3-C5 and 8G3-B5, were generated by using hybridoma technology and their isotypes were characterized. MAb 6B3-C5 was chosen as the detector antibody and conjugated with quantum dots. Based on MAb 6B3- C5 labeled with quantum dots, a modified dot blot assay was developed for the on-site determination of V. anguillarum. It was found that the method had no cross-reactivity with other than V. anguillarum bacteria. The detection limit (LOD) for V. anguillarum was 1 × 10(3) CFU/ml in cultured bacterial suspension samples, which was a 100-fold higher sensitivity than the reported colloidal gold immunochromatographic test strip. When V. anguillarum was mixed with turbot tissue homogenates, the LOD was 1 × 10(3) CFU/ml, suggesting that tissue homogenates did not influence the detection capabilities. Preenrichment with the tissue homogenates for 12 h could raise the LOD up to 1 × 10(2) CFU/ml, confirming the reliability of the method.

Development of colloidal gold immunochromatographic signal-amplifying system for ultrasensitive detection of Escherichia coli O157:H7 in milk

A colloidal gold immunochromatographic signal-amplifying test strip with a sandwich format was successfully developed to detect Escherichia coli O157:H7.

Advantages of fluorescent microspheres compared with colloidal gold as a label in immunochromatographic lateral flow assays

Label selection is of vital importance for immunochromatographic assays. In this study, the fluorescent microsphere test strip and colloidal gold immunochromatographic test strip (FM-ICTS and CG-ICTS) were developed for the detection of Escherichia coli O157:H7 on the basis of the sandwich format. Two types of labels, namely, colloidal gold particles (CG) and carboxyl-modified fluorescent microspheres (FMs), were compared while coupling with anti-E. coli O157:H7 monoclonal antibody (mAb). The FM-ICTS and CG-ICTS were also compared. Results show that the coupling rate between FMs and mAb was higher than that between CG and mAb. Under optimum conditions, the sensitivity of FM-ICTS was eight times higher than that of CG-ICTS. Approximately 0.1μg of mAb was used in every FM-ICTS, whereas 0.4μg of mAb was used in every CG-ICTS. The coefficient of variation of FM-ICTS and CG-ICTS was 4.8% and 16.7%, respectively. The FM-ICTS and CG-ICTS can be stored at room temperature for 12 months and specific to five E. coli O157:H7 strains. Milk sample inoculated with E. coli O157:H7 were tested by the FM-ICTS and CG-ICTS. The FM-ICTS sensitivity was 104CFU/ml while the CG-ICTS sensitivity was 105CFU/ml. The sensitivity, consumption of antibodies, and coefficient of variation of FM-ICTS were better than those of CG-ICTS for the detection of E. coli O157:H7.

Development of a colloidal gold immunochromatographic test strip for detection of lymphocystis disease virus in fish

To develop a gold immunochromatographic test strip for on-site rapid detection of lymphocystis disease virus (LCDV). Monodispersional colloidal gold and gold-labelled anti-LCDV monoclonal antibody (McAb) 2D11 were prepared and characterized by UV-visible spectroscopy and transmission electron microscopy. Gold-labelled probe was used as the detection antibody, and goat anti-mouse IgG at the control line and anti-LCDV McAb 1A8 at the test line of the test strip served as the capture antibody. The positive results could be easily judged by the presence of a red test line with naked eye within 10min. The test strip, in good agreement with enzyme-linked immunosorbent assay and dot-blotting in sensitivity and LCDV detection, gave a detection limit of 1μgml(-1) of LCDV and was stable for 6months at room temperature and 12months at 4°C. The test strip was specific, simple and convenient for rapid detection of LCDV presenting good stability and reproducibility. This ready-to-use test strip allows on-site rapid detection of LCDV in fish without the requirement of specialized equipments and professional personnel, which could augment the practical application for diagnosis of LCDV even in disadvantage areas.

Detection of survivin in esophageal cancer patients' serum with colloidal gold immunochromatography

Objective To investigate the feasibility of screening for esophageal cancer with survivin colloidal gold immunochromatographic test strip. Methods The serum samples from 158 esophageal cancer patients and 146 healthy individuals were tested with survivin colloidal gold immunoohromatographic test strips. Results 20 nm-diameter colloidal gold solution was prepared and survivin polyclonal antibodies with different concentrations were labeled to the gold particles. It showed that the optimal concentration for labeling was 12 μg/ml. The prepared survivin colloidal gold immunochromatographic strip teat showed positive rates of survivin in esophageal cancer group and control group were 51.9 % (82/158) and 15.1% (22/146) respectively (χ2 = 45.7, P 0.05), gender groups (male: 50.4%, female: 58.1%, χ2= 0.59, P > 0.05) , primary site groups (upper segment: 56.3%, middle segment: 46. 1%, lower segment: 32. 1%, χ2 = 2.64, P > 0.05), differentiation groups (well-differentiation: 56.3%, moderate differentiation: 43.2%, poor-differentiation: 32.7%,χ2= 1.63, P >0.05)and lymph node metastasis groups (with metastasis:43.3%, without metastasis:43.4%, χ2 = 0.00, P > 0.05). The sensitivity, specificity and accuracy of survivin colloidal gold immunochromatographic test strip was 51.9% (82/158), 84.9% (124/146) and 67.8% (206/304) respectively. Conclusions Survivin colloidal gold immunochromatographic test strip is fast, simple, easy-to-read. It could be used as a valuable tool for screening of high-risk patients with esophageal cancer. Key words: Survivin; Test strip; Colloidal gold; Immanochromatography; Esophageal cancer

Comparison of a new gold-immunochromatographic assay for the detection of antibodies against avian influenza virus with hemagglutination inhibition and agar gel immunodiffusion assays

A gold-immunochromatographic test-strip kit is used for the detection of IgG antibodies against the nucleocapsid protein of Avian Influenza Virus (AIV). Compared with the “gold standard”, i.e. hemagglutination inhibition (HI) and agar gel immunodiffusion (AGID) assays, the gold-immunochromatographic test strip has many advantages, such as high specificity, high sensitivity, convenience, is rapid and has low cost. The gold-immunochromatographic test strip provides a unique tool for the on-site surveillance and diagnosis of Avian Influenza.