Papers by Keyword: ELISA

Abstract: We have successfully developed gold nanoparticle based immunostrip assay to detect protein-A (PA). Rabbit polyclonal antibody IGg (αPA) that has affinity to PA was conjugated to gold nanoparticles (GNPs) and the gold nanoconjugate (αPA-GNP) was used to detect protein-A by simple immunostrip assay method. ELISA experiments were used to confirm the retention of binding affinity of antibody towards protein-A after conjugation with gold nanoparticles.

Abstract: This study aimed to develop a method for the detection of tetrodotoxin (TTX) based on monoclonal antibody (McAb). The hapten TTX was linked to carrier protein keyhole limpet hemocyanin (KLH) as immunogen, and linked to ovalbumin (OVA) as coating antigen by the Mannich method. Then the 6~8 weeks Babl/c mice were immunized. After cell amalgamation, a cell line with high specificity and sensitivity was obtained, and McAb was produced. The indirect competitive enzyme-linked immunosorbent assay (icELISA) was developed for detecting TTX. The optimized working conditions of the icELISA were 4.0 μg/mL coating antigen, 0.75 μg/mL McAb, 45 min competitive time, at room temperature (20~25 °C). The IC₅₀ value of this method was 24.0 ng/mL, the working ranges were 5.2~107.6 ng/mL, the intra-assay and inter-assay coefficient of variation (CV %) were 4.2 and 4.5, respectively. This investigation will benefit the assay kit development for detecting TTX.

Abstract: In the Enzyme-linked immunosorbent assay (ELISA) test, many steps need traces pipetting. The ELISA test results will be different when we use different pipetting ways. Our traces pipetting system is based on the air displacement pipetting principle, comparable to the functioning of hand pipettes. It is applied pressure sensor to realize pressure-based liquid level detection (pLLD) and aspiration monitoring. The monitored system can distinguish the following situations: (1) a correct aspiration; (2) cup empty; (3) tip-blocked; (4) bubbles. Using the air displacement principle into traces pipetting can avoid contamination or dilution by system liquids, and problems with corroded tubing, pumps, etc. It applied pressure sensor to realize pLLD and aspiration monitoring. The results of the real-time monitor module on air displacement pipetting show that the traces pipetting system can agilely distinguish the different liquid pipetting situations. The method of air displacement pipetting offered an effective way for ELISA traces pipetting system.

Abstract: Human-like collagen (HLC) is giant molecule bio-protein which produced by gene engineering. The biology characteristic of HLC is very special, such as the faction about good biocompatibility, cell adhesion, to promote new cell formation and cellula epithelialis formation, and hemostatic function. In this article we adopt the traditional method to produce the polyclonal antibody which injected the antigen into BALB/C mouse. And use the ELISA to detect the valence of antibody. Then prepare the polyclonal antibody for the purpose of gives us a convenience and dependable method to detect the product.

Abstract: The qualitative ELISA was used for screening out atrazine in soil and positive results were proved with GC-MS. The recoveries 、Precision and the detection limits were estimated in this paper. The average recoveries of ELISA were 96.64%~98.06%,and coefficient of variations were 1.69%~3.36%,the detection limit was 0.04μg/kg, while The average recoveries of GC-MS were 85.78%~87.46%,and coefficient of variations were 4.3%~6.56%,the detection limit was 0.03μg/kg, when the concentrations of 0.5,1.0,5.0μg/kg atrazine standard were add to soil samples. Then three positive samples that filtered by ELISA were proved with GC-MS, and the results were coherent between two methods. The assay found ELISA is a rapid and exact method with good reproducibility for atrazine determination in soil .

Abstract: Aim In this study, the adaptability of an ELISA kit for quantification the residual BSA in TEMPs, the influence of rinsing protocol on reducing the residual BSA in TEMPs and the effectiveness of ultra-filtration on reducing the matrix effects of TEMPs immersion on BSA quantitative by ELISA were discussed. Methods Three kinds of TEMPs used in this study were: tissue engineered skin (TES), recombination human acellular dermal matrix (rhADM) and combination chitosan tissue engineered skin (cC-TES). The devices were rinsed according to the Directions for Use firstly. To investigating the influence of rinsing protocol on reducing the residual BSA in TEMPs, TES were rinsed by two different protocols separately. Then TEMPs immersions were prepared according to ISO10993.12, physiological saline (NS) was used as immersion medium. BSA concentration in immersions and filtrate were determined by using the “Quantitative measure of residual BSA ELISA kit” (detection range was 12.5-200ng/mL, manufactured by WUXI BOSHENG MEDICAL BIO-TEC DEVELOPMENT CO., LTD. As suspected to have some matrix effect on BSA quantification by ELISA kit, rhADM immersion was ultra-filtrated before detection. Results The results showed good correlation between dilution factors and the A450nm of TES and cC-TES immersions, correlation coefficient (r) was 0.9943±0.0007 and -0.9835±0.0037, respectively. No significant effect on BSA detection was found when NS was used as immersion medium. Comparing the results of protocol 1 and 2, the A450nm of TES immersion was significantly decreased after rising by protocol 2. After ultra-filtration, the correlations between absorption and dilution factors of rhADM immersion were improved significantly; the correlation coefficient (r) was raised from -0.7264±0.0089 to -0.9606±0.0039. Conclusions The quantitative ELISA kit was considered to be adaptability for detect the BSA in TEMPs. Different rinsing protocol may obviously affect on reducing the residual BSA in TEMPs. The matrix effects of rhADM immersion can be reduced obviously by using ultrafiltration.

Abstract: Plastic substrates were modified with 2-methacryoyloxyethyl phosphorylcholine (MPC) copolymer brushes by surface-initiated atom transfer radical polymerization (ATRP) with a mean chain density of 2.44 chains/nm2 and a chain length around 50nm. Ellipsometry, X-ray photoelectron spectroscopy, gel permeation chromatography, nuclear magnetic resonance and atomic force microscopy were used to characterize the modified surfaces.
MPC was copolymerized with a methacrylate monomer including an active ester unit which can link covalently with antibodies. They latter were immobilized on these well-defined surfaces for characterization and a further use in enzyme-linked immunosorbent assay (ELISA).
All kinds of surfaces displayed a good density of immobilized antibodies mainly forming globular packs of around 500 units. A water-soluble MPC polymer-based stabilizer added to the antibody solution could further their individual immobilization.

Abstract: Lactate dehydrogenase (LDH) and enzyme-linked immunosorbent assay (ELISA) have attracted much attention recently for the evaluation of blood compatibility of biomaterials due to their convenience and quantifiability. In this paper, the use of LDH and ELISA is described for in situ investigation of platelet behavior on biomaterial surfaces, including quantification of platelet adhesion and platelet activation, after suitable testing conditions have been established. The material samples investigated in these tests included low temperature isotropic carbon (LTIC), Ti-O films, and phosphorus- and aluminum-doped TiO2 films. The evaluation results show that the lowest platelet adhesion and activation are observed on phosphorus-doped TiO2 films while the highest platelet adhesion and activation are observed on LTIC. In addition, conventional platelet adhesion experiments were performed for comparison, and yielding similar evaluation results as LDH and ELISA. It is suggested that LDH and ELISA tests can be successfully applied to evaluate the blood compatibility of biomaterials and can show many advantages, such as quantification, reliability and objectivity, compared with conventional platelet adhesion test.

Abstract: The goal of this study was to investigate release tendency of brain-derived neurotrophic factor (BDNF) from poly(L-lactide-co-glycolide) (PLGA) and small intestine submucosa (SIS) scaffold prepared by ice-leaching method. A porous scaffold consisting of PLGA and SIS as carrier of BDNF has been prepared in the presence of ice particle. SEM image of the PLGA/SIS scaffold showed an interconnected pore structure. The release behavior of BDNF loaded PLGA/SIS scaffold was examined for 4 weeks period at phosphate buffered saline (PBS, pH 7.4) at 37 oC. The sustained release of BDNF over 4 weeks was observed from the PLGA/SIS scaffold. These results indicate that the sustained release of BDNF from PLGA/SIS scaffold can be very useful for application in the tissue engineering.