Immunoassay human serum albumin

Catalase has also been used as an enzyme label in competitive heterogeneous enzyme immunoassays. Catalase generates oxygen from hydrogen peroxide with the oxygen determined amperometrically with an oxygen electrode. This approach has been demonstrated for a-fetoprotein theophylline and human serum albumin... 

Reagents for Enzyme-Immunoassay. Tris buffer contained 0.05 M Tris (hydroxymethyl) aminomethane, pH 7.5 0.05, with 0.1% human serum albumin and 0.01% sodium azide. The H O -methanol fixative contained 0.3% in absolute methanol prepared just before use... 

Instead of using human serum albumin as a carrier protein, other workers (135) utilized ovalbumin for preparing the diazotized clenbuterol antigen in an enzyme immunoassay developed for screening of clenbuterol residues in bovine urine, liver, and eye. Alkaline phosphatase rather than -galactosidase was also used as an enzyme label in the preparation of the enzyme-clenbuterol conjugate. 

Heineman s group [13,14] proposed the method of heterogeneous immunoassay to detect human serum albumin (HSA) labeled with In... 

Mohamadi et al. [96] reported online preconcentration of human serum albumin (HSA) and its immunocomplex with a monoclonal antibody on-chip coupled to isotachophoresis. The sample injection, preconcentration, and separation were carried out continuously and controlled by a sequential voltage switching program. Preconcentration was carried out with on-chip nondenaturing gel electrophoresis in methylcellulose solution. Furthermore, the authors applied this method for immunoassay of HSA. The separation of HSA and its immunocomplex was achieved in 25 seconds in 1 cm of the microchannel with induced fluorescence detection at 7.5 pM. 

II. Ikariyama, Y., Suzuki, S., andAizawa, M., Luminescence immunoassay of human serum albumin with hemin as labeling catalyst. Anal. Chem. 54, 1126-1129 (1982). 

L7. Lim, C. S., Miller, J. N., and Bridges, J. W., Energy-transfer immunoassay A study of the experimental parameters in an assay for human serum albumin. Anal. Biochem. 108, 176-184 (1980). 

One of the earliest efforts of qualitative measurement of a protein (human serum albumin) in a microchip-based device was based on bead agglutination in a microchamber (approximately lOjaL). Subsequently, several quantitative immunoassays have been performed using microchip electrophoretic systems that permit separation and quantitation of free- and bound-labeled antigens in competitive assays (see Chapter 5). Most are carried out in channels micro-machined into fused silica substrates. Early work on quantitative assays achieved measurement of cortisol in serum.The assay used cortisol labeled with fluorescein and an argon laser detector at 488 nm and required only 80 pL of a 40x dilution of serum as the sample. Other capillary electrophoresis-based assays for a variety of antibodies have also been developed that include immunoglobulins (IgG, IgA, and IgM), antibovine serum albumin, and antiestradiol. ... 

Direct measurement of T3 by immunoassay has been made possible by the production of T3 specific antibodies. Unlike T4 antiserum, high-titer, specific T3-antiserum is seldom obtained by immunization of rabbits with naturally occurring Tg. Good-quahty antiserum, however, has been produced using Ts-enriched Tg, Ts-human serum albumin (HSA), or Tj-bovine serum albumin (BSA) conjugates. Monoclonal T3 antibodies have also been produced using hybridoma technologies. 

In homogeneous competitive assays the electrode-active group of the labeled antigen is masked by the bound antibody. Such electrochemical immunoassays have been developed for human serum albumin (HSA) (Alam and Christian, 1982,1985). HSA was labeled with Pd2+ or Zn2+, and the bound metal ion was measured by differential pulse polarogra-phy at a mercury electrode. Binding of antibody caused a drop of the peak current. 

Immunoassays for human serum albumin (HSA) have been based on HSA labeled with Pb (Alam and Christian, 1982), Co " (Alam and Christian, 1984), and Zn (Alam and Christian, 1985). The metal ion bound to the HSA can be detected with differential pulse polarography by reduction at a mercury electrode. The peak current for the labeled HSA decreases on binding with Ab, which is the basis for the immunoassay. 

IgE antibodies were first implicated in an anaphylactic reaction to chlorhexidine in Japan in 1986. Specific skin-sensitizing IgE antibodies to chlorhexidine were demonstrated in the patients sera by passive transfer and by an immunoassay using paper discs conjugated to chlorhexidine linked to human serum albumin. Dose-dependent inhibition of IgE antibody binding to the chlorhexidine-solid phase by both chlorguanide and the parent drug demonstrated specificity of the reaction. Attempts to identify chlorhexidine allergenic determinants were initiated nearly 20... 

Figure 1 The protocol for metal-label based immunoassay for human serum albumin (HSA) using releasable In. ...

ADP AFP ab as ALAT AP ASAT ATP BQ BSA CEH CK CME COD con A CV d D E E EC ECME EDTA EIA /e FAD FET FIA G GOD G6P-DH HBg HCG adenosine diphosphate a-fetoprotein antibody antigen alanine aminotranferase alkaline phosphatase aspartate aminotransferase adenosine triphosphate benzoquinone bovine serum albumin cholesterol ester hydrolase creatine kinase chemically modified electrode cholesterol oxidase concanavalin A coefficient of variation (relative standard deviation) layer thickness diffusion coefficient enzyme potential Enzyme Classification enzyme-chemically modified electrode ethylene diamine tetraacetic acid enzyme immunoassay enzyme loading factor flavin adenine dinucleotide field effect transistor flow injection analysis amplification factor glucose oxidase glucose-6-phosphate dehydrogenase hepatitis B surface antigen human chorionic gonadotropin... 

Pilot human dosimetry studies have demonstrated the usefulness of adduct measurements in exposure assessments. Higher adduct levels in heavily exposed coke oven workers compared to those with lower exposures or controls have been reported using USERIA (3 )> ELISA (36) or the P-post1abe1ing assay (41). Tobacco consumption is also positively correlated with adduct formation (49). Chemotherapeutic trials are among the best evidence that adduct levels are related to exposure because in these cases, negative controls are truly negative. The development of immunoassays for cisplatin-DNA adducts by Poirier et a1., have led to internal dosimetry estimates and predictions for prognosis (35). Levels of aflatoxin B -adducts have also been identified in human liver and breast with ELISA (40.871. in serum albumin with RIA (88) and ELISA (38)- Multiple adduct assessments are also feasible (Table III) (89). 

---