Nonintrusively Measured Temperature Distributions as Evidence for Free Convection in Immunoassay Incubation

Beumer, and Tom; Timmerman, Brenda H.

doi:10.1021/ac970661n

Cited by 3 publications

(1 citation statement)

References 8 publications

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“…Several strategies have been adopted to speed up this process. Beads in the 1−3 μm diameter range are frequently used, as they provide an advantageous surface-to-volume ratio and also can be conveniently renewed. , Elevation of temperature − is sometimes applied, but this does not provide a significant increase in the overall mass transport efficiency. Another approach is to minimize the diffusion distances by decreasing the size of the reactors.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Protein Adsorption and Immunosorption Kinetics in Photoablated Polymer Microchannels

et al. 2000

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A preliminary characterization of protein adsorption and immunosorption kinetics carried out in polymer microchannels is reported. A photoablated poly(ethylene terephthalate) (PET) surface and a PET/polyethylene sealing laminate were used for the channel microfabrication. The surface state of the PET channel substrate and PET/polyethylene lamination were analyzed by using SEM and ATR-FTIR spectroscopy techniques. Protein adsorption and immunosorption studies were carried out using staphylococcal enterotoxin B (SEB) and polyclonal anti-SEB antibody (Ab) samples. Affinity purified polyclonal rabbit (Rb) anti-SEB Ab was radioiodinated and adsorbed in the microchannel. It was determined that the maximum amount of adsorbed antibody was about 13.0 pmol·cm-2 (about 2 μg·cm-2), which corresponds to 0.81 pmol per microchannel. The distribution of the adsorbed protein on the walls of the microchannel depended on the surface state of the polymer exposed to the solution. The amount of the radiolabeled antibody adsorbed on the photoablated PET was about 19.4 pmol·cm-2, whereas it was only 5.5 pmol·cm-2 on the PET/polyethylene lamination. About 30% of the anti-SEB Ab adsorbed on the microchannel surface was found to be biologically active. A study of the kinetics of the SEB−anti-SEB Ab immunochemical reaction was also carried out. It could be substantiated that the forward reaction is diffusion controlled and that the equilibrium for such a reaction could be achieved within about 1 min in the microchannels. This is in good agreement with the calculation of a diffusion-controlled reaction in such a microchannel, according to Fick's second law.

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Section: Introductionmentioning

confidence: 99%

Characterization of Protein Adsorption and Immunosorption Kinetics in Photoablated Polymer Microchannels

et al. 2000

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Immunoassays

1999

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The term "immunoassay" refers to a diverse group of analytical techniques which are found throughout clinical laboratories. In this article, an immunoassay is defined as an analytical method that uses antibodies or antibody-related reagents for the determination of sample components. The selective nature of antibody binding allows these reagents to be employed in the development of methods that are highly specific and that can often be used directly with even complex biological matrixes such as blood, plasma, or urine. By combining the selectivity of antibody-analyte interactions with the vast array of antibodies that can be produced in nature and the availability of numerous readily detectable labels (e.g., radioisotopes or enzymes), immunoassays can be designed for a wide variety of analytes while also providing low limits of detection. These characteristics, along with the relatively low cost generally associated with these methods, have continued to make immunoassays a popular method in many clinical applications.Many of the trends that were discussed in an earlier report on immunoassays (A1) have continued throughout the period of this current review. Some of these continuing trends include an emphasis on nonradioactive labels, more specific reagents, and improved formats for automating or performing immunoassays. The purpose of this article is to examine recent advances in the theory and analytical methodology of immunoassays, as represented by articles that appeared between January 1997 and December 1998. In this review, immunoassays are primarily categorized on the basis of the type of label that they employ (e.g., radioimmunoassays, enzyme immunoassays, etc.). Besides considering new developments that have occurred in each type of immunoassay, other topics will be discussed, such as advances that have been made in the theory of immunoassays or immunoassay reagents. Related items, including immunosensors and commercial immunoassay instrumentation, will be discussed elsewhere. GENERAL BOOKS AND REVIEWSA variety of materials appeared during this review period on the general topic of immunoassay methods. A book presenting an overview on immunoassays was edited by Price and Newman (A2). The present and possible future status of immunoassays was also discussed in several articles and book chapters (A3-A5). Appleby and Reischl reviewed some of the common types of immunoassays, with an emphasis on those that use monoclonal antibodies (A6). An overview of immunoassay automation was given by Gorman et al. (A7). General clinical applications of immunoassays that were reviewed included the use of these methods in toxicology and drug analysis (A8-A13) or in immunoscreening procedures (A14). Several papers focused on immunoassay measurements involving particular groups of clinical analytes, such as psychotropic drugs (A15), cardiac drugs (A16), markers for myocardial damage (A17), gonadotropins (A18), prostanoids or leukotrienes (A19), and chiral drugs (A20). Related techniques that were discussed included those invol...

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