"Delfia" and "Amerlite": two sensitive nonisotopic immunoassay systems for assay of thyrotropin compared.

Abstract We assessed the LKB "Delfia" (time-resolved dissociation-enhanced lanthanide fluoroimmunoassay) and the Amersham "Amerlite" (enhanced luminescent immunometry) assays of thyrotropin in serum. Both assays are sensitive (respective detection limits: 0.02 and 0.04 milli-int. unit/L) and have very good within- and between-batch precision over a wide range of thyrotropin concentrations. Results by the two methods correlate well (r = 0.992); the regression equation is: Amerlite = 0.915 Delfia - 0.33 milli-int. unit/L. The standard curve for the Delfia assay was linear, but that for the Amerlite assay showed some deviation from linearity below 0.5 milli-int. unit/L. Both assays have a negative bias in comparison with radiolabeled immunoradiometric assays, as judged by results for samples from the Quality Assurance Scheme. Both assays discriminate well between hyper-, hypo-, and euthyroid subjects, and results for thyrotropin for most patients with nonthyroidal illness were within the euthyroid reference interval. Both assays are convenient to perform and are based on systems that provide a viable alternative to radioimmunoassay.

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Water virology external quality assurance scheme: experiences over four years

Water Science & Technology ◽

10.2166/wst.1997.0780 ◽

1997 ◽

Vol 35 (11-12) ◽

pp. 471-473

Author(s):

J. Sellwood ◽

J. Shore

Keyword(s):

Quality Control ◽

Quality Assurance ◽

External Quality Assurance ◽

Recreational Water ◽

External Quality ◽

Wide Range ◽

Virus Recovery ◽

Assurance Scheme ◽

Quality Assurance Scheme ◽

Stringent Quality

The Water Virology External Quality Assurance (EQA) Scheme has distributed samples containing enterovirus to the specialised virus laboratories in Britain which analyse recreational water. Duplicate samples were either assayed for direct virus count or added to 101 of water, concentrated to 10ml and then assayed for virus counts. Although similar counts were obtained in different laboratories on direct assays, a wide range of virus counts was reported after water processing. However, robust attention to method detail and stringent quality control has been shown to improve the consistency of virus recovery rates. The results of tests for enterovirus in recreational water can then be used with confidence.

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Methods for the analysis of premium livestock grains

Australian Journal of Agricultural Research ◽

10.1071/ar98166 ◽

1999 ◽

Vol 50 (5) ◽

pp. 775 ◽

Cited By ~ 24

Author(s):

D. S. Petterson ◽

M. Choct ◽

C. J. Rayner ◽

D. J. Harris ◽

A. B. Blakeney

Keyword(s):

Quality Assurance ◽

Environmental Factors ◽

Reference Materials ◽

Chemical Constituents ◽

Laboratory Evaluation ◽

Evaluation Program ◽

True Value ◽

Wide Range ◽

Assurance Scheme ◽

Quality Assurance Scheme

The literature contains a wide range of reported values for the content of most chemical constituents of feed grains and meals. It is not possible to assess accurately how much of this variation is due to genotypic and environmental factors and how much to differences in methodologies between laboratories. We have reviewed the literature for the preparation and analysis of feed grains (cereals, legumes, and oilseeds) and made recommendations for procedures considered to give the most accurate and reliable results. Recommendations are also made for a quality assurance scheme, an inter-laboratory evaluation program, and the use of reference materials. Australia-wide adoption of these practices should ensure that any future variations observed can be ascribed to genotype and/or environment. This review is part of a national premium feed grains quality project which, in turn, is part of a program to provide more accurate and reliable information about the true value of our feed grains to the domestic and international feeds industries.

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Determination of thyrotropin in serum by time-resolved fluoroimmunoassay evaluated.

Clinical Chemistry ◽

10.1093/clinchem/31.10.1706 ◽

1985 ◽

Vol 31 (10) ◽

pp. 1706-1709 ◽

Cited By ~ 33

Author(s):

H L Kaihola ◽

K Irjala ◽

J Viikari ◽

V Näntö

Keyword(s):

Specific Activity ◽

High Specific Activity ◽

Reference Interval ◽

Time Resolved ◽

Standard Curve ◽

Highly Sensitive ◽

Wide Range ◽

Sandwich Type ◽

Serum Tsh

Abstract We evaluated a new, highly sensitive time-resolved fluoroimmunoassay for thyrotropin (TSH) in serum. This direct immunometric "sandwich"-type assay involves two monoclonal antibodies against TSH, one immobilized, the other labeled with europium. Extremely high specific activity of the label and the use of labeled antibody in large excess make the method sensitive enough to measure TSH values falling below the normal reference interval. The standard curve is nearly linear over a wide range of TSH concentrations (standard concentrations range from 0.25 to 324 milli-int. units/L). The lowest concentration detectable was 25 micro-int. units/L. The CV for the assay was less than 6% at 0.5 milli-int. unit/L or higher, 11.3% at 0.1 milli-int. unit/L. For a CV of 10% the lower limit of the working range would be around 0.1 milli-int. unit/L. The interassay CV was 6.7 to 11.8% for TSH concentrations of 0.31 to 19.6 milli-int. units/L. The 95% confidence interval for sera from 111 healthy persons was 0.6-3.8 (range 0.3-3.8) milli-int. units/L. For hyperthyroid patients and thyroid cancer patients treated with thyroxin after thyroidectomy, serum TSH values were all below the reference interval (most were less than 25 micro-int. units/L).

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