TSH assay


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assay

 [as´a]
determination of the purity of a substance or the amount of any particular constituent of a mixture.
biological assay bioassay; determination of the potency of a drug or other substance by comparing the effects it has on animals with those of a reference standard.
CH50 assay a test of total complement activity as the capacity of serum to lyse a standard preparation of sheep red blood cells coated with antisheep erythrocyte antibody. The reciprocal of the dilution of serum that lyses 50 per cent of the erythrocytes is the whole complement titer in CH50 units per milliliter of serum.
enzyme-linked immunosorbent assay (ELISA) any enzyme immunoassay using an enzyme-labeled immunoreactant (antigen or antibody) and an immunoadsorbent (antigen or antibody bound to a solid support). A variety of methods are used for measuring the unknown concentration, such as either competitive binding between the labeled reactant and unlabeled unknown or a sandwich technique in which the unknown antigen binds both the immunoadsorbent and labeled antibody. One of the uses of ELISA is to screen blood for antibody to the human immunodeficiency virus; a positive result indicates probable exposure to the virus and possibly that the virus is in the blood. Since false-positives can occur, a back-up test is used to confirm positive findings.
 ELISA: With antigen capture ELISA, the wells are coated with antibody to the virus. The sample containing virus (1) is added and, after washing several times, enzyme conjugated to an antibody to the virus is added (2). Finally, after a further cycle of washing, the enzyme's substrate (3) is added. A colored product is formed if the viral antigen is present in the sample (4). From Hart and Shears, 1997.
microhemagglutination assay–Treponema pallidum (MHA-TP) a Treponema pallidum hemagglutination assay using microtechniques; used in the detection of syphilis.
radioreceptor assay a radioligand assay in which a radiolabeled hormone is used to measure the concentration of specific cellular receptors for the hormone in tissue specimens, an example being radioassay of estrogen receptors in breast tissue.
thyroid-stimulating hormone assay thyroid-stimulating hormone test.
Treponema pallidum hemagglutination assay (TPHA) a treponemal antigen serologic test for syphilis using tanned sheep red blood cells coated with antigen from the Nichol's strain of Treponema pallidum and treated patient serum; it is similar in sensitivity and specificity to the FTA-ABS test. This test is not useful for individuals who have had syphilis in the past.

TSH assay

thyroid-stimulating hormone test.
References in periodicals archive ?
In fact, third-generation TSH assays may present more problems than the old [T.
In the noncompetitive format of the Roche total TSH assay, this would typically result in a signal increase, opposite of our findings.
Alan McNeil for the Bayer ADVIA Centaur TSH assays, and Angela Chiriano for the Bayer ACS:180 TSH assays.
1) refers to a second-generation thyrotropin (TSH) assay on the ADVIA Centaur and not to a third-generation TSH assay.
A comparison of different sample matrices for evaluating functional sensitivity, imprecision and dilution linearity of the Abbott ARCHITECT i2000 TSH assay.
Interference from heterophilic antibodies has been described previously with other TSH assays (7-10).
Moreover, we found no difference in the estimates of EOR/Gy for hypothyroidism in the groups measured by different TSH assays (data not shown).
Now, a team researchers led by Randy Polson, PhD, from the University of Utah has developed a device that uses an iPhone's LED flash, digital camera with collimating lens to optimize illumination and focusing, and a specially-designed app to collect an image of a completed TSH assays and, and convert the image into a quantitative TSH values.
Complicating this is the fact that current TSH assays differ in specificity for recognising different circulating TSH isoforms and that this can give rise to a 1.
Thus, in the absence of sensitive TSH assays, a serum [FT.
Thyroid-stimulating hormone testing is the preferred approach because: 1) TSH is central to the negative-feedback system; 2) small changes in serum thyroid function cause logarithmic amplification in TSH secretion; and (3) the most advanced (third-generation) chemiluminescent TSH assays can now detect both elevation and significant lowering of TSH levels, and are capable of reliably measuring values <0.