Horseradish peroxidase antibody label

Key Words Antibody horseradish peroxidase conjugation labeling periodate oxidation. 

In tyramide signal amplification (TSA), the target cells are labelled with an antibody or a nucleic acid probe, followed by secondary detection with a horseradish peroxidase (HRP) labelled antibody. HRP activates multiple copies of fluores-cently labelled tyramide derivatives, yielding fluorescent tyramide radicals that are deposited in the vicinity of the HRP-target interaction site (Fig. 5). 

A similar strategy of premixing antibody and enzyme-labeled antigen prior to the injection into the immunochromatographic column has been used in a competitive assay performed to quantitate insulin by photometric detection using a horseradish peroxidase (HRP)-labeled insulin. Antiantibody immobilized on the chromatographic support was used to capture the Ab-Ag-label complex. In this way 1.7 x 10 M insulin can be detected [119]. 

Wutz et al. (2011) developed for the first time a multianalyte immunoassay based on an automated flow-through CL microarray technique for identification and quantification of antibiotic derivatives in honey samples using regenerable antigen microarrays, an indirect competitive immunoassay format using horseradish peroxidase (HRP)-labeled antibodies and CL read-out with a CCD camera. The method allows the analysis of four analytes (enrofloxacin, sulfadiazine, sulfamethazine, and streptomycin) simultaneously in 8 min with adequate recoveries and without purification or extraction. Due to the regenerability of the microarray each chip could be individually calibrated before the analysis and allowed more than 40 assays, which reduces the costs per analysis and permits an automated work flow in routine laboratories. 

Conventional ion-selective electrodes have been used as detectors for immunoassays. Antibody binding measurements can be made with hapten-selective electrodes such as the trimethylphenylammonium ion electrode Enzyme immunoassays in which the enzyme label catalyzes the production of a product that is detected by an ion-selective or gas-sensing electrode take advantage of the amplification effect of enzyme catalysis in order to reach lower detection limits. Systems for hepatitis B surface antigen and estradiol use horseradish peroxidase as the enzyme label and... 

Secondary antibody and determination. A secondary antibody labeled with an enzyme is added which binds to the primary antibody that is bound to the coating antigen. If the primary antibody were produced in a rabbit, an appropriate secondary antibody would be goat anti-rabbit immunoglobulin G (IgG) conjugated with horseradish peroxidase (HRP) (or another enzyme label). Excess secondary antibody is washed away. An appropriate substrate solution is added that will produce a colored or fluorescent product after enzymatic conversion. The amount of enzyme product formed is directly proportional to the amount of first antibody bound to the coating antigen on the plate and is inversely proportional to the amount of analyte in the standards. 

L. Alfonta, A.K. Singh, and I. Willner, Liposomes labeled with biotin and horseradish peroxidase a probe for the enhanced amplification of antigen-antibody or oligonucleotide-DNA sensing processes by the precipitation of an insoluble product on electrodes. Anal. Chem. 73, 91-102 (2001). 

Enzyme labels are usually coupled to secondary antibodies or to (strept)avidin. The latter is used for detection of biotinylated primary or secondary antibodies in ABC methods (see Sect. 6.2.1). Enzyme labels routinely used in immunohisto-chemistry are horseradish peroxidase (HRP) and calf intestinal alkaline phosphatase (AP). Glucose oxidase from Aspergillus niger and E. coli (3-galactosidase are only rarely applied. 

Horseradish peroxidase (HRP) an enzyme routinely used in immunohisto-chemistry for labeling antibodies. Histochemichal detection of peroxidase is based on the conversion of aromatic phenols or amines, such as diamino-benzidine (DAB), into water-insoluble pigments in the presence of hydrogen peroxide (H202). 

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