Immunoassay serum thyroxine

Gl. Galen, R. S., and Forman, D., Enzyme immunoassay of serum thyroxine with the AutoChemist multichannel analyzer. Clin. Chem. 23, 119—121 (1977). 

M6. Miyai, K., Ishibashi, K., and Kawashima, M., Enzyme immunoassay of thyroxine in serum and dried blood samples on filter paper. Endocrinol. Jpn. 27, 375-380 (1980). 

Y4. Yamamoto, R., Hattori, S., Inukai, T., Matsuura, A., Yamashita, K., Kosaka, A., and Kato, K., Enzyme immunoassay for thyroxine and triiodothyronine in human serum, with use of a covalent chromatographic separation method. Clin. Chem. 27, 1721-1723 (1981). 

CapenCC (1992) Pathophysiology of chemical injury of the thyroid gland. Toxicol Lett 64-65 P381-388 Chopra IJ, Solomon DH, Ho RS (1971) A radio-immunoassay of thyroxine. J Clin Endocrinol 33 865-868 Chopra IJ (1972) A radioimmunoassay for the measurement of thyroxine in unextracted serum. J Clin Endocrinol Metab 34 938... 

Schmalzing D, Koutny LB, Taylor TA, Nashabeh W, Fuchs M. Immunoassay for thyroxine (T4) in serum using capillary electrophoresis and micromachined devices. J Chromatogr, B Biomed Sci Appl 1997 697 175-180. 

Finley, P.R. WiUiams, R.J. Lichti, D.A. Evaluation of a new homogeneous enzyme-inhibitor immunoassay of serum thyroxine with use of a bichromatic analyzer. Clin. Chem. 1980, 26, 1723-1726. 

Serum thyroxine has been precisely measured by selected ion monitoring as its methyl ester-N,0-bis(tri-fiuoroacetyl) [119, 120] and methyl ester-KO-bis(hepta-fluorobutyryl) derivatives [121] in connection with the application of isotope dilution GC-MS as a reference method to control the results obtained from less specific immunoassay methods. The fragment ions monitored are in the higher mass range of around 800 amu, with little interference. 

Examples of method I are the immunoassay for biotin [121], for serum thyroxine [122], and for hepatitis B surface antigen [123]. Conjugates used were the isoluminol derivatives (6), (7), and (8)... 

Competitive immunoassay was also conducted for serum T4 (3,5,3, 5 -tet-raiodo-L-thyroxine) on a fused silica chip. Again a T4-releasing agent (TAPS) was used to release T4 from serum [152]. 

Free Thyroxine. Measurement of free T4 radioimmunoassay in dried blood samples has been found to be useful to avoid false-positive results for low TBG in neonatal hypothyroid screening. Enzyme immunoassay of free T4 in serum was developed by Weetall et al. (W7) and subsequently by us (16). 

Chopra IJ, Solomon DH, Ho RS (1972) Competitive ligandbinding assay for measurement of thyroxine-binding globulin (TBG). J Clin Endocrinol 35 565-573 DSL Diagnostic Systems (2005) Multispecies endocrine assay cross-reactivity information New Resource from DSL - AnimalDx.com. [Internet resource] http //www.dslabs.com/temp/animaldx.htm Larsen PR (1972) Direct immunoassay of triidothyronine in human serum. J Clin Invest 51 1939-1949 Larsen PR (1972) Direct immunoassay of triidothyronine in human serum. J Clin Invest 51 1939-1949 Levy RP, Marshall JS, Velayo NL (1971) Radioimmunoassay of human thyroxine-binding globuline (TBG). J Clin Endocrinol Metab 32 372-381... 

EN19 Danielson, S.J., Brummond, B., Babb, B., Tyminski, P., Birecree, J., Fyles, J. and Pratt, L. (1991). Measurement of total thyroxine in serum or plasma by thin-film enzyme immunoassay. Clin. Chem. 37, 1034, Abstr. 594. 

Immunoassay kits using luminol and arylacridinium ester labels have been developed by nine companies for a variety of thyroid, steroid and pituitary hormones, viruses, digoxin, and creatine kinase. One assay for total and free thyroxin has detection limits of 20 pM in serum, while another for total and free triiodothyronine has a 3-pM detection limit in serum. These analytes are used as clinical indicators of thyroid gland malfunction. While research has shown that... 

Danielson S, Warren K, Birecree J, Fyles J, Hermann S, PonticeUo N, et al. Measurement of total thyroxine in serum using a thin-film slide en2yme immunoassay. Clin Chem 1994 40 1024A. 

Greene H, Hwang D, Hutchins J, Johnson A. Techni-con thyroxine and thyroid binding globulin Two fuHy automated immunoassays for the determination of total thyroxine and TBG in human serum, Clin Chem 1990 36 1082. 

Madsen K, Schulkamp K, Bellet N. Homogeneous enzyme immunoassay for the measurement of serum or plasma thyroxine. Clin Chem 1986 32 1163. 

Nelson JC, Nayak SS, Wilcox B. Variable underestimates by serum free thyroxine (T,) immunoassays of free concentrations in simple solutions. J Clin Endocrinol Metab 1994 79 1371-5. 

The competitive principle of immunoassays can be applied to nonimmuno-logic systems. Any substance that can bind specifically to a macromolecule can be measured using the principle of competitive protein binding. The specific binding macromolecule can be a serum protein such as thyroxine binding globulin, a specific receptor, or an antibody. 

Lee, D. E., V. J. Salerno, S. V. Lamb, and T. J. Reimers. 1998. Clinical evaluation of immunlite chemiluminescent immunoassays in total thyroxine (TT4) thyrotropin (TSH) and free-thyroxine (FT4) in dog serum. Clinical Chemistry 44 (SuppL) A108. 

A fifth group of procedures includes the use of an array format. The usual 96-well plate for immunoassay measures the fluorescence in liquid phase either by determining the unbound fraction or by dissolving the bound reporter molecules to overcome problems related to autofluorescence, scattering, and back-reflection, although the selection of an appropriate solid support allows for the measurement of the fluorescence directly on the solid surface. For example, a heterogeneous fluoroimmunoassay using fluorescein-labeled antibodies for total thyroxin in serum uses this procedure. 

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