Enzyme-linked immunosorbent assay controls

Atrazine, used as a selective pre- and post-emergence herbicide to control annual weeds in several crops, is the most representative compound of this group. It is also used as a non-selective herbicide in non-crop areas. After absorption, the compound is metabolized to dealkylated and deisopropy-lated derivatives. The unchanged compound and its metabolites are excreted in urine, where they can be detected by chromatography or enzyme-linked immunosorbent assay (Lucas et al., 1993). A mercapturic acid conjugate of atrazine has also been found in urine samples of workers spraying this herbicide (Lucas et al., 1993) (Table 6). 

B.) The yield of recombinant HSA, as determined using an enzyme-linked immunosorbent assay (ELISA). The sprouts were germinated in an airlift bioreactor tank for 175 hours in the presence or absence of 20 mM KN03. Recombinant HSA was expressed under the control of the Rbc56 promoter isolated in our laboratory. 

The traditional microbiological methods are very time consuming and sometimes limited concerning their interpretation. For that reason fast analysis methods as well as automated methods have been developed the latter are often used in specialised microbiological laboratories. During the last few years more and more modern biotechnological methods have been implemented into quality control, for example the enzyme-linked immunosorbent assay or more recently the polymerase chain reaction, which allows the detection of very specific microorganisms. 

Macrolides are obtained by controlled submerged aerobic fermentations of soil microorganisms. Although species of Streptomyces have dominated, species of Saccharopolyspora, Micromonospora, and Strep toverticillium are also well represented. New techniques such as enzyme-linked immunosorbent assay (ELISA) may prove beneficial for discovering new structures. 

Enzyme immunoassays (EIA) play an important role in clinical diagnostics, veterinary medicine, environmental control, and bioprocess analysis. Antibodies are coupled to enzymes like peroxidase or phosphatase, whose products can be measured after the degradation of a substrate. Because of its high selectivity and sensitivity, EIA enables the detection of a broad spectrum of analytes in complex samples. A solid phase EIA performed in a plastic microtitre plate is called an enzyme-linked immunosorbent assay (ELISA). The coloured products produced in the ELISA can be measured spectro-photometrically rather than in a scintillation counter as for the RIA. 

Enzyme-Linked Immunosorbent Assay Both competitive and sandwich ELlSAs are available. Although the competitive ELISA is faster because it uses only one incubation with an antibody, it is reported to be less sensitive and exhibits large imprecision. ELISA can be performed on a microplate reader, allowing semiautomation. In the sandwich assay, the primary antibody (antialbumin antiserum) is fixed on the plastic plate, which is then washed. Samples, controls, and calibrators are added, and the complexes detected and quantified by a second antibody conjugated to an enzyme label. 

Screening methods for Water data InFormaTion in support of the implementation of the Water Framework Directive Water Framework Directive Screening Methods/Emerging Tools Enzyme-Linked ImmunoSorbent Assays Quality Control/Quality Assurance Square Wave Anodic Stripping Voltametry... 

Enzyme-linked immunosorbent assays (ELISAs) have long been used to quantify cytokines and other proteins that are secreted from cells. ELISAs enable the user to assay multiple samples, to obtain reproducible quantitative results, and to design studies with quantifiable endpoints. Intracellular activities intimately involved in apoptosis, such as control of mitochondrial permeability to holocytochrome c and activation of a specific caspase, are quantified by the ELISAs described in this chapter. The cytochrome c ELISA is generally used to quantify the activities of the proteins belonging to the Bcl-2 family. The active caspase ELISA quantifies a specific active caspase among a background of latent caspase and other active caspases. 

Enzyme linked immunosorbent assays (ELISA) have been successfully developed for the detection and quantitation of the BT kurstaki and BT israelensis toxins (11-14). These ELISA are used routinely to supplement bioassays in monitoring the production and quality control during fermentation process. Reported here are the laboratory studies of the application of ELISA for monitoring the BT toxin in environmental samples. 

After more than two decades, advances in IHC have provided a feasible approach to performing immunostain-ing on routinely processed tissues, such that this method is now routine for the performance of IHC special stains in surgical pathology laboratories using EEPE tissues (see Appendix lA). However, demands for improved reproducibility and for quantification have led to a growing recognition that IHC has the potential to be more than just a special stain. If properly controlled in all aspects of its performance, IHC can provide a tissue-based immunoassay with the reproducibility and quantitative characteristics of an ELISA (enzyme-linked immunosorbent assay) test, which not only detects the presence of an analyte (protein or antigen) but also provides an accurate and reliable measure of its relative or real amount (see Quality Control and Standardization section). 

Asensio L, Gonzalez I, Garcia T, Martin R (2008). Determination of food authenticity by enzyme-linked immunosorbent assay. Food Control, 19(1) 1-8. 

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