immunosorbent assay

Multiple enzyme linked immunosorbent assay system on a capillary-assembled microchip integrating valving and immuno-reaction functions [An article from: Analytica Chimica Acta]
$10.95
This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Multiple enzyme linked immunosorbent assay (ELISA) chip is developed by using capillary-assembled microchip (CAs-CHIP) technique, which involves simple embedding of 2-3mm length of square capillaries possessing valving and immuno-reaction functions into the microchannels fabricated on a PDMS substrate. In contrast to the previously reported ELISA chips, our system enables not only the flexible design of the multi-ELISA chip required for many different diagnostic purposes, but also the valving operation required for a reliable analysis. Here, a thermo-responsive polymer-immobilized capillary was used together with a small Peltier device, as a valving part, and different antibody-immobilized capillaries were used as immuno-reaction part. Sample solution and detecting reagent solutions were sequentially introduced through the valving capillary, and the valve is closed to completely stop the solution flow inside the immuno-reaction capillaries and detected using thermal lens microscope (TLM). Different anti-IgGs (human, goat, chicken) were immobilized and used as ELISA parts of CAs-CHIP. Sequential introductions of the mixed IgG solution, mixed enzyme-antibody solution and substrate solution facilitated the multiple determinations of 0.1ngmL^-^1 IgGs (human, goat, chicken) with total analysis time of about 30min. The valve-integrated multi-ELISA chip developed here can be applied for many different diagnostic purposes by using different immuno-reaction capillaries necessary for a specific clinical diagnostic application.

Direct sub-ppt detection of the endocrine disruptor ethinylestradiol in water with a chemiluminescence enzyme-linked immunosorbent assay [An article from: Analytica Chimica Acta]
$8.95
This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
A chemiluminescence ELISA for the direct detection of ethinylestradiol (EE2) in water at sub-ppt levels was developed and validated. At a signal-to-noise ratio of three the detection limit is 0.2+/-0.1ngL^-^1, at a ratio of 10 the LOQ is found to be 1.4+/-0.8ngL^-^1. Based on a conservatively calculated precision profile the analytical working range is established from 0.8 to 100ngL^-^1. The ELISA was tested in four different matrices, including surface water and effluent of sewage treatment plants. All measurements were validated using an LC-MS/MS method. Typical results were consistent in both methods below 1ngL^-^1. Using this chemiluminescence ELISA facilitates for the first time the direct detection of EE2 at ecotoxicologically relevant concentrations.

Development and validation of an enzyme-linked immunosorbent assay for vitellogenin in Chinese loach (Misgurnus angaillicaudatus) [An article from: Environment International]
$10.95
This digital document is a journal article from Environment International, published by Elsevier in 2005. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
A competitive enzyme-linked immunosorbent assay (ELISA) was developed for the quantification of vitellogenin (Vtg) in the plasma of Chinese loach (Misgurnus angaillicaudatus). Vtg was isolated by anion exchange membrane chromatography from the plasma of 17@b-estradiol (E"2)-treated loach. Polyclonal antibody against Vtg was raised in rabbits, and the specificity of the antibody was assessed by Western blotting analysis. No cross-reactivity was observed with plasma from male loach. Plasma samples from vitellogenic females and E"2-treated males were diluted parallel with the purified Vtg standard curve in the ELISA. The detection limit of the assay was 5.7 ng ml^- ^1 and a working range of the standard curve was between 15.6 and 1000 ng ml^- ^1. The intra- and inter-assay coefficients of variations were 6.9% and 10.4%, respectively. The recovery was 104.4%. The assay was applied for measuring vitellogenin concentration in the plasma from 24 wild Chinese loach from Lianyungang, Jiangsu Province, in October 2003. It was found that, in addition to females (plasma Vtg concentration ranging from 518.4 @mg ml^- ^1 to 1922.3 @mg ml^- ^1), male loach showed low plasma Vtg-from undetectable (two fish) to 2.9+/-0.7 @mg ml^- ^1 (mean+/-S.D.). The results indicate that this method provides a valuable tool for the study of estrogenic effect in Chinese loach.

A rapid and sensitive chemiluminescence enzyme-linked immunosorbent assay for the determination of fumonisin B"1 in food samples [An article from: Analytica Chimica Acta]
$10.95
This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
An enzyme-linked immunosorbent assay (ELISA) based on polyclonal antibody with enhanced chemiluminescent (ECL) detection of fumonisin B"1 (FB"1) in food samples has been developed. Assay conditions, including concentrations of antibody and enzyme conjugate, competition time and so on, were optimized. The effects of pH and two different organic solvents were investigated. The optimized ECL-ELISA system allowed FB"1 determination in a linear working range of 0.14-0.9@mgL^-^1 with IC"5"0 value of 0.32@mgL^-^1 and a limit of detection of 0.09@mgL^-^1. The ECL-ELISA was about 10 times more sensitive and about 30% time less than that of colorimetric ELISA using the same antibody and HRP-conjugate. Good recoveries with spiked food samples were obtained, and the results correlated well with those obtained using conventional direct competition ELISA assay and HPLC method, which indicated that ECL-ELISA was capable of being applied for the specific detection and routine monitoring of FB"1 in food samples.