Thyroxine-binding globulin, enzyme immunoassay

Frc. 9. A typical standard curve for enzyme immunoassay of thyroxine-binding globulin (TBG) in dried blood samples on filter paper. [Cited from Hata et al. (H4).[... 

H4. Hata, N., Ito, M., Mizuta, H., Nose, O., and Miyai, K., Enzyme immunoassay of thyroxin-binding globulin in dried blood samples on filter paper. Clin. Chem. 29, 1437-1440 (1983). 

Standard radio-immunoassay procedures are applied, nowadays mainly solid phase assays which can be rapidly performed and evaluated, they are also several enzyme-linked immunoassay (ELISA) procedures from commercial suppliers. It is recommended to perform an internet check for the most appropriate method at the time of the study (for example DSL 2005). Methods have been described for triiodothyronine (Nejad et al. 1975, Chopra etal. 1972a, Larsen 1972a, 1972,) and for thyroxin (Chopra etal. 1971, Chopra 1972). The use of assays based on thyroxin binding globulin (Chopra et al. 1972b) is no longer recommended and cannot be applied to the rat, because the rat does not have this binding protein. However, for the human, measurement... 

Alkaline phosphatase is one of the most suitable enzymes for electrochemical immunoassays owing to its high turnover number and broad substrate specificity. Different substrates have been used, but 4-aminophenyl phosphate is most suitable, since the reaction product, 4-aminophenol is easily oxidized without fouling of the electrode surface. Thyroxine-binding globulin, cortisol, and prostatic acid phosphatase have been detected by using alkaline phosphatase. 

W22. Wood, W. G., Rohde, C, and Jacobs, A., A comparison of commercially available luminescence enhanced enzyme immunoassay with in-house non-radioisotopic assays for thyroxine binding globulin and total thyroxine. J. Clin. Chem. Clin. Biochem. 26, 135-140 (1988). 

McCormack G> Faix J. Evaluation of chemiluminescent enzyme immunoassay for thyroid binding globulin (TBG) and comparison of T4/TBG ratio with free thyroxin index. Clin Chem 1990 36 1149. 

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