Biorecognition assay

Currently, many biopharmaceuticals, which are proteins in many cases, are produced in many bioindustry fields, and the measuring of the concentrations and bioactivities of these products is thus becoming essential in bioindustry. We have added a new section for Biorecognition assay in Chapter 11, and we explain the fundamental aspects of biorecognition and its application for the measurement of bioproducts at low concentrations. In this edition, we have included some examples and some new problems to assist in the progress with learning how to solve problem. 

Brewster JD, Lightfield AR. Rapid biorecognition assay for herbicides in biological matrices. Anal... 

All DNA hybridization assays are subject to cross-hybridization, in which an oligonucleotide that is not a perfect sequence match hybridizes with the capture probe. The cross-hybridization in the OFRR was investigated using samples of oligonucleotides with either 0-, 1-, 2-, 5-, or 25-base mismatches when compared with the 25 base-pair biorecognition capture probe. The resulting resonant mode spectral shifts for the respective mismatch are plotted in Fig. 14.7b. The measurements show a difference of 1.3 pm and 2.8 pm for one and two base-pair... 

There are three major components of the MAMEF technique 1) plasmonic nanoparticles (i.e., silver, gold, copper, nickel, aluminum, zinc, etc.), 2) microwaves and 3) an aqueous assay medium. TTie plasmonic nanoparticles serve as (i) a platform for the attachment of one of the biorecognition partners (anchor probes) (ii) as an enhancer of the close-proximity fluorescence signatures via surface plasmons (i.e., MEF effect) [2] and (iii) a material not heated by microwaves for the selective heating of the aqueous media with microwave energy. 

In search of both sensitivity and practicability of the assay, the reaction pathway and the particular mechanism of inhibition may preliminarily determine the particular detection principle. Without exception, most common detection techniques have been implemented with this biorecognition principle, employing varied assay formats using either batch mode or any modality of flow injection analysis. 

Wilchek, M. Hofstetter, H. Hofstetter, O., The application of biorecognition, In Novel approaches in biosensors and rapid diagnostic assays Liron, E. Ed. Kluwer/Plenum New York, 2000... 

In the sandwich assay format, two biorecognition elements directed to either the same epitope present multiple times on the analyte surface or the different epitopes on the target analyte are utilized. For immunoassays, this format is useful for large analytes with multiple antigenic sites. Here, one antibody is immobilized onto a porous membrane and serves as the capture antibody, while the other is conjugated to a detectable species. The response is directly proportional to the concentration of analyte in the sample. A band consisting of a secondary antibody may also be present to serve as a control that the assay components worked and the assay was run correctly. This assay format is depicted in Fig. 4. 

Compound Sensor system Detection limit Detection time (min) Biorecognition element and assay format Detection matrix Refs. 

Choice of biorecognition element. What biorecognition element will be used Is it tailored for the application The use of materials (e.g., antibodies) produced for other assay formats often results in poor-quality sensors, as the properties of the antibody may not be customized for the format chosen. 

Should an assay format be used with both class and analyte-specific biorecognition units ... 

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