Antibodies detection using

Indirect Assay Competition for Antibody Detection Using a Single Dilution of Test Serum... 

In SSC, antinuclear antibodies detected using immunofluorescence are present in 95% of patients. 

There is a choice of secondary antibody detection using either of the following methods (for a discussion of these methods, see above) ... 

Chemiluminescent Immunoassay. Chemiluminescence is the emission of visible light resulting from a chemical reaction. The majority of such reactions are oxidations, using oxygen or peroxides, and among the first chemicals studied for chemiluminescence were luminol (5-amino-2,3-dihydro-l,4-phthalazinedione [521-31-3]) and its derivatives (see Luminescent materials, chemiluminescence). Luminol or isoluminol can be directly linked to antibodies and used in a system with peroxidase to detect specific antigens. One of the first appHcations of this approach was for the detection of biotin (31). 

Most sample components analyzed with electrophoretic techniques are invisible to the naked eye. Thus methods have been developed to visualize and quantify separated compounds. These techniques most commonly involve chemically fixing and then staining the compounds in the gel. Other detection techniques can sometimes yield more information, such as detection using antibodies to specific compounds, which gives positive identification of a sample component either by immunoelectrophoretic or blotting techniques, or enhanced detection by combining two different electrophoresis methods in two-dimensional electrophoretic techniques. 

Figure 7.7. Protein microarray on polyvinylidene difluoride filters (PVDF). Proteins are gridded on filter and probed with an antibody to a gene of interest. Protein-ligand interactions could be detected using a labeled ligand as a probe.

Biochips can be used for either measuring differential expression between two populations or for testing for the presence of a DNA sequence (resequencing). Protein chips have been applied in expression profiling and antibody detection, binding specificities of a protein expression library and protein-protein interactions. 

F.C. Gong, Z.J. Zhou, G.L. Shen, and R.Q. Yu, Schistosoma japonicum antibody assay by immunosens-ing with fluorescence detection using 3,3, 5,5 -tetramethylbenzidine as substrate. Talanta 58, 611-618 (2002). 

Optical imaging methods for hypoxia are not yet applicable in vivo but immunohistochemical antibody detection of nitroimi-dazoles (e.g. pimonidazole) has been used extensively for in vitro work and biopsy tissue staining (89). 

The performance of a biotreatment system ultimately depends on optimization of the activity of microbes and the ability to control the process parameters of the treatment system [157]. In this respect, the ability to monitor gene copy numbers and gene expression is highly useful for real time optimization of the efficiency of a biotreatment system. Advanced molecular techniques as well as low cost methods (e.g., antibody detection of enzymes based on color reaction strips fluorescence i.e., GFP marked organisms with UV light detection) can also be applied to monitor the microbial community structure, persistence of the added bacteria, and their interactions with indigenous populations. 

Optimization of the immunoassay was performed with respect to tracer and antibody concentrations to obtain the required sensitivity. These conditions differed depending on the detection system used photographic detection required higher antibody and tracer concentrations than when the plate luminometer was used. A further complication arose from the very low affinity of the tracer for the antibody when using an antibody dilution of 1 3000 and a tracer dilution of 1 4000 less than 1% of the tracer was bound after a 2-h incubation. This means that the antibody, in the absence of clenbuterol, binds less than 10 pg of the... 

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