Horseradish peroxidase conjugate acid

The working principle of the ELISA described here involves the use of LHRH peptide-coated wells to capture any anti-LHRH antibodies present in the sera of vaccinated mice. Captured antibodies are detected through the use of a horseradish peroxidase-conjugated antibody that is specific for mouse immunoglobulins and a substrate is then added to induce a color change. In this case, the substrate utilized is 2,2 -azino-bis 3-ethylbenzthiazoline-sulfonic acid (ABTS Sigma-Aldrich, USA), which is converted to a green soluble end product by horseradish peroxidase (see Note 7). The level of substrate-induced... 

An indirect enzyme-linked immunosorbent assay (ELISA) was developed for maduramicin in poultry feed. The assay utilized polyclonal anti-maduramicin antibody raised in rabbits, maduramicin monoamide with 1,6-hexane diamine-conjugated ovalbumin as the coating antigen, horseradish peroxidase conjugated goat anti-rabbit IgG and 2,2 azinobis(3-ethylbenzthiazoline) sulfonic acid (ABTS) for quantitation. Standard curves ranging from 0 to 80 ng/mL maduramicin were constructed. The assay did not cross-react with monensin, lasalocid, salinomycin, lincomycin, narasin, chlortetracycline or roxarsone. Broiler feed fortified at 4 to 7 ppm maduramicin were shown to be quantifiable by ELISA at an average recovery of 98.1%. This ELISA method for maduramicin in poultry feed is comparable to the established HPLC-F method. 

Some cell lines have endogenous alkaline phosphatase activity (especially carcinoma lines). In this case, horseradish peroxidase-conjugated goat antimouse IgG can be used (substitute in step 14 of Subheading 3.1.) with appropriate substrate (e.g., 2,2 -azino-di-[3-ethyl-benzthiazoline-6-sulfonic acid] [ABTS]). 

An enzyme-immunoassay for testosterone in female plasma and saliva uses lla-hydroxytestosterone 11-hydrogen succinate-horseradish peroxidase conjugate as enzyme label, and p-hydroxyphenylacetic acid to provide a fluorimetric end-point . A solid-phase enzyme-immunoassay has been described for 19-norethisterone, based upon the lla-hydrogen succinoyloxy derivative. ... 

Aptamer based biosensors, for example for recombinant human erythropoietin (as model analyte), can be made more sensitive by amplification with a boronic acid tethered gold nanoparticle that is then associated with an alkaline phosphatase to produce a redox active probe molecule. A similar re-usable bio-immuno-sensor has been suggested for carcinoembryonic antigen. A phenylboronic acid is assembled on gold to (reversibly) bind the antibody horseradish peroxidase conjugate. Interaction with the antigen slows down the hydrogen peroxide reduction. An HIV-1 immunoassay based on electroluminescence has been proposed by Zhou etaV In this process the... 

Behzadi, G., Kalen, P., Parvopassu, R Wiklund, L. (1990). Afferents to the median raphe nucleus of the rat retrograde cholera toxin and wheat germ conjugated horseradish peroxidase tracing, and selective D-[3H]aspartate labelling of possible excitatory amino acid inputs. Neuroscience 37, 77-100. 

In each of these methods, undiluted serum, urine, acid-deproteinized milk, or a buffered saline extract of muscle was mixed with sulfamethazine-horseradish peroxidase and added to antibody-coated wells of a microtiter plate. A sulfamethazine-bovine serum albumin conjugate prepared by the glutaraldehyde procedure (56) was used for antibody production. Results showed that screening of serum was of value since sulfamethazine concentrations in serum directly correlated with those in swine tissues. Thus, for example, a level of 100 ppb of sulfamethazine in... 

The CARD approach uses horseradish peroxidase to catalyze the deposition of tyramide molecules that are conjugated to an antihapten immunoglobulin or Streptavidin, which in turn, during the first incubation step, binds to the digoxigenin- or biotin-labeled nucleic acid target. Thus, the number of target sites for the next reaction step is markedly increased. 

The conjugation of the AuNPs can be also performed with antihuman IgG peroxidase conjugate under the same experimental conditions. Then, the MB sandwich immunocomplex can be carried out without AuNP (MB/anti-human IgG/Human IgG/ anti-human IgG-HRP) and with AuNP (MB/anti-human IgG/ Human IgG/AuNP/anti-human IgG-HRP) and finally analyzed spectrophotometrically, to evaluate the benefits in using AuNPs. The spectrophotometric analysis is based in the oxidation of o-phe-nylenediamine (OPD) catalyzed by the horseradish peroxidase (HRP) bound to AuNPs, which generates a product with maximum absorbance at 492 nm in acidic solution. In the case of the sandwich carried out with AuNP, an enhancement of the signal is... 

Shimomura et al. used a Biacore 2000 SPR sensor instrument (Biacore AB, Sweden) for detection of PCB 3,3 4,4, 5-pentachlorobiphenyl [32]. They employed competition assay format and the sensor chip with polyclonal antibodies immobilized in the dextran matrix. The sample was mixed with a conjugate of PCB-horseradish peroxidase (HRP) and injected into the sensor. The presence of the analyte was detected as a decrease in binding of PCB-HRP conjugate. The detection was performed in 15 min with a detection limit of 2.5 ngmL in buffer. The sensor was demonstrated to be regenerable by 0.1 M hydrochloric acid. 

Immunoassay. All samples were analyzed for trlazlne herbicides using RES-I-MUNE Immunoassay kits (ImmunoSystems Inc., Scarborough, Maine). The kits use polyclonal antibodies coated on the walls of polystyrene test tubes and an atrazine-enzyme conjugate prepared by covalently binding atrazine to horseradish peroxidase by a modified carbodilmide technique (12-13. Other reagents in the immunoassay kits include three standards (negative control, 0.1 ug/L atrazine solution and 1,0 ug/L atrazine solution), substrate, chromogen, and a "stop" solution of 2.5 N (normal) sulfuric acid. 

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