Antibodies incorporation

Electrophoretic elution and "switch" monoclonal antibodies are combined in a new rapid recycle method an affinity-mediated membrane transport process reported by Dall-Bauman and Ivory (8). In this modeling paper, a "switch" monoclonal antibody incorporated into a supported liquid membrane is used to facilitate the transport of human growth hormone from a high-pH to a low-pH environment. Electrochemical effects, including Donnan equilibria between the membrane and external environments, and imposition of external electrical fields, significantly affected the flux of protein across the membrane. Experimental confirmation of the simulation results could introduce affinity-mediated transport as a powerful new biospecific separation method. 

Potentiometric electrodes have been used as transducers in biosensors in which a thin layer containing enzymes, antibodies, or whole cells separates the electrode surface from the analyte solution and provides selective recognition properties. Thin layers containing enzymes or cells catalyze reactions that cause the localized production or consumption of the species to which the electrode responds. Antibodies, incorporated into immunosensors, have been shown to cause small but measurable signals upon antigen binding, but usually require a label (such as an enzyme) that allows catalysis of a reaction that can be followed potentiometrically [13]. 

The efficiency of antibody incorporation into the cells electroporated using this method can be determined several ways. The concentration of antibody can be detected by Western blotting of the cell extracts, using an anti-mouse antibody for monoclonal and anti-rabbit antibody for polyclonal antibody (Fig. 1), and quantitated by densitometry. Electroporation efficiency can also be determined by flow cytometry. Fluorescein isothiocyanate (FITC)-labeled antibody can be used for electroporation, and the percentage of fluorescent cells can be determined with a fluorescence-activated cell sorter. 

The first two categories, clarifying and crossflow filters, have been very well developed and optimized for use in biotechnology and standard wastewater treatment applications. Equipment is easily available for these applications, whether as small 0.2 micron sterilizing filter used to terminally sterilize 100 ml of product solution, or a small 500 ml crossflow filter used to concentrate a small amount of antibody solution. Many vendors of this equipment to wastewater treatment applications have their origins in the CPI (Chemical Process Industries), and have incorporated many of the scale-up and optimization properties developed in much larger units used in large scale chemical production. As a result, these two filtration unit operations are one of the most optimized and efficient used in wastewater treatment. 

Consider an isotope of yttrium, Y-90. This isotope is incorporated into cancer-seeking antibodies so that the cancer can be irradiated by the yttrium and destroyed. How many neutrons are in... 

Universal anti-Rh sera deprived of anti-A or B-antibodies were prepared by contacting A and B-immunoadsorbents with human blood sera. To achieve zero titer in the Coombs agglutination test a portion of immunoadsorbent (80-160 mg) proportional to the initial serum titer (1 8-1 64, 1 ml) is required. The incorporation of A-immunoadsorbent into anti-B sera did not interfere with their titer and vice versa, Under the same circumstances an anti-Rh serum titer is lowered by one step or remains unchanged [125], Properties of this composite sorbent are therefore promising for its use in extracorporal hemisorption processes. 

When liposomes are formed, they can be made to entrap certain compounds inside themselves, eg, drugs and isolated genes. There is interest in using liposomes to distribute drugs to certain tissues, and if components (eg, antibodies to certain cell surface molecules) could be incorporated into liposomes so that they would be targeted to specific tissues or tumors, the therapeutic impact would be considerable. DNA entrapped inside liposomes appears to be less sensitive to... 

The remarkable selectivity that is inherent in the reaction of an antibody with the antigen or hapten against which it was raised is the basis for the extensive use of immunoassay for the rapid analysis of samples in clinical chemistry. Immunochemical reactions offer a means by which the applicability of potentiometric techniques can be broadened. A number of strategies for incorporating immunoassay into the methodology of potentiometry have been explored... 

An electrode in which an antibody or an antigen/hapten is incorporated in the sensing element is termed an immunoelectrode . The potential response of the immuno-electrode is based on an immunochemical reaction between the sensing element of the electrode and antibody or antigen/hapten in the sample solution. One example of such an electrode is the polymer membrane electrode shown in Fig. 7. The selective response of this electrode to specific immunoglobulins is based on the interaction between antibody in solution and an antigen-ionophore complex in the membrane ... 

Another subset of SPE is immunoaffinity extraction, in which an antibody specific to the analyte is incorporated into the SPE sorbent. This technique is very selective to the analyte and would be very effective in separating the marker residue from tissue-related matrix components. Disadvantages of immunoaffinity extraction are the need to develop a specific antibody-based SPE for each analyte. This approach holds promise for the future as the development of antibody-based methods becomes more commonplace. 

Direct and indirect competition formats, illustrated in Figure 1, are widely used for both qualitative and quantitative immunoassays. Direct competition immunoassays employ wells, tubes, beads, or membranes (supports) on to which antibodies have been coated and in which proteins such as bovine semm albumin, fish gelatin, or powdered milk have blocked nonspecific binding sites. Solutions containing analyte (test solution) and an analyte-enzyme conjugate are added, and the analyte and antibody are allowed to compete for the antibody binding sites. The system is washed, and enzyme substrates that are converted to a chromophore or fluorophore by the enzyme-tracer complex are added. Subsequent color or fluorescence development is inversely proportionate to the analyte concentration in the test solution. For this assay format, the proper orientation of the coated antibody is important, and anti-host IgG or protein A or protein G has been utilized to orient the antibody. Immunoassays developed for commercial purposes generally employ direct competition formats because of their simplicity and short assay times. The price for simplicity and short assay time is more complex development needed for a satisfactory incorporation of the label into the antibody or analyte without loss of sensitivity. 

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