Papers by Keyword: ELISA

Abstract: By now there is no effective treatment for a number of socially significant bacterial and fungal diseases. β-(1→3)-glucans are the principal components of the cell wall of fungi, including Candida albicans, Aspergillus fumigatus and other. At the same time, β-(1→3)-glucans are absent in mammals and man, that makes them promising components of carbohydrate-protein conjugated vaccines for the prevention and treatment of fungal infections. Alginic acid, constructed of β-(1→ 4)-linked mannuronic acid are extracellular polysaccharides produced by Pseudomonas aeruginosa. The protein CRM197 is a non toxic derivative of diphtheria toxin, which is widely used as a safe carrier in conjugated vaccines. The purpose of this study was to investigate the antigenic activity of experimental samples of the conjugated vaccines based on synthetic oligosaccharide ligands and CRM197 carrier protein in the competitive enzyme-linked immunosorbent assay. Two-time immunization Balb/c mice with experimental samples of the conjugated vaccines induced the formation of high titers of specific antibodies. High antibody’s avidity to their oligosaccharide ligands was shown in competitive ELISA. These data suggest the relevance of further preclinical trials of the conjugated antifungal vaccine against Candida and Aspergillus and antibacterial vaccine against Pseudomonas.

Abstract: Mollusc shells are organic-inorganic composites that are often preserved in the fossil record. However, the way the organic fraction, also called shell matrix, gets fossilized remains an unsolved question, in spite of several old and more recent studies. In the present paper, we have tried to mimic a diagenetic process by constantly heating for ten days at 100°C fresh nacre powder samples of the Polynesian pearl oyster Pinctada margaritifera. Each day, aliquots of nacre powder were sampled and the matrix was subsequently extracted. It was further analysed by direct weigh quantification, by immunological techniques and by proteomics. Our preliminary data suggest that nacre proteins, when heated at 100°C in dry condition, degrade rather slowly. We evidenced a differential degradation pattern of the soluble and insoluble fractions, and showed that some nacre proteins of the insoluble fraction are stable after ten days of heating. Factors that influence the diagenetic stability of some shell proteins are discussed.

Abstract: Two immunological methods, ELISA and CLIA were optimized and compared. The sensitivity of CLIA was higher. The optimized CL-ELISA allowed the Sudan I detection in a linear range of 0.156-5 ng mL^-1, the IC₅₀ was 0.642ng mL^-1 and the limit of detection (LOD) was 0.05ng mL^-1. The method showed good recoveries with spiked chili powder. The recovery rate range from 97.28-112.39%. The proposed method proved to be efficient for the detection of Sudan I in food samples.

Abstract: Enzyme-Linked ImmunoSorbant Assay (ELISA) is a dioxin screening test method, which has several advantages such like low setup cost, low analysis cost, low technical barriers, simple operation, and short analysis time. The case study of this study is a dioxin contaminated site. ELISA was applied in this site due to its widely contaminated range, numerous surveys, and short remediation period. The experience earned in this case study could be the reference for similar pollution site in the future.

Abstract: A chemiluminescence enzyme-linked immunosorbent assay (CL-ELISA) was developed for the detection of Sudan I in food products. The CL-ELISA conditions, such as the concentration of antigen, antibody and goat anti-mouse IgG-HRP, were optimized. The optimized CL-ELISA allowed the Sudan I detection in a linear range of 0.625-10 ng mL^-1, the IC₅₀ was 3.3ng mL^-1 and the limit of detection (LOD) was 0.31 ng mL^-1. The method showed good recoveries with spiked chilli powder. The recovery rate in a batch range from 73-109.6%, and the recovery rate between the batch range from 78-109.24%. The proposed method proved to be efficient for the detection of Sudan I in food samples.

Abstract: Deoxynivalenol (DON) mimotope, designated as CDON, is an epitope (CMRPWLQ) immunoscreened from a phage-displayed random peptide library. In order to replace the conjugated toxin with non-toxic recombinant proteins in ELISA, two novel expression vectors, which were designated as plasmid pGEX-CDON and phagemid pC89S4-CDON for producing GST-CDON and pVIII-CDON fusion proteins in E.coli were constructed. After purification, both GST-CDON and pVIII-CDON fusion proteins show good reactogenicity with an anti-DON antibody in a competitive inhibition ELISA test. When GST-CDON was used as coating antigen, the linear range of the competitive inhibition ELISA is from 62ng/ml to 410ng/ml, the linear equation is Y= 186.6-23.87Ln (X), IC₅₀ is 194ng/ml. For pVIII-CDON as coating protein, the linear range of the competitive inhibition ELISA is from 20ng/ml to 470ng/ml, the linear equation is Y = 161.3-25.49Ln (X), R2=0.9962, IC₅₀ is 94ng/ml. ELISA analysis and comparison show the reactogenicity and specificity of pVIII-CDON binding to anti-DON antibody are better than GST-CDON fusion protein. The pVIII-CDON is promising in establishing an ELISA without the use of the toxic mycotoxin conjugate.

Abstract: In the Enzyme-Linked ImmunoSorbent Assay(ELISA) test, automatic pipetting for liquid samples is key factor to improve test efficiency and quality. In this paper, a multi-channel pipetting system used to perform pipetting and incubation automatically is constructed, which is equipped with three-dimensional motion platform and four pipetting channel. The system contains electronic control system based on DSP, which communicates with ELISA host software by USB. The experiment demonstrates the effectiveness of this multi-channel pipetting system.

Abstract: The paper establishes the basic framework of the software system: firstly, the principles used by the automatic immunoenzymatic analytic system are introduced, and then design the main functional modules. This system is developed in Visual C++ 6.0 environment and takes the style of Windows XP, achieved in the whole Chinese operation interface for bulk sample detecting and data processing, making the automation of adding sample, dilution, incubation temperature, cleaning, calculate results come true, finally in the graphics, curve, data and other forms display test results and instrument working condition.

Abstract: Polyclonal antibody against streptomycin was prepared by using a streptomycin–bovine serum albumin conjugate for the immunization of rabbits. Using this antibody, we developed quantitative assays for streptomycin by means of an indirect competitive enzyme-linked immunosorbent assay (icELISA). Fifty percent inhibition concentration (IC₅₀) for the antibody was 3.6 ng/ml. The detection limit was 0.4 ng/ml. The average of recoveries for all samples was 86.14% and the coefficients of variation of intra- and inter-assays were below 18%. The detection limit using the kit was 15 ng/ml in animal feeds.

Abstract: The CD-ELISA is a self-contained micro-device that incorporates low-power micro-fluidic components and high-sensitivity immune-molecules, and is capable of performing parallel and multiple tests with high precision. The CD platform integrates number of micro-fluidic functions. Bio-detection area is the most important region which directly affects measurement results. In this study, both theoretical and experimental results were compared to show the feasibility design of bio-detection region.