Reagent analyte-specific

IVDs developed for use at a single site and offered commercially only at that site are considered laboratory testing services, in-house tests, or so-called "home brew" tests. These have historically been a widely used practice for test development, and a broad menu of tests is available in this mode. These tests are subject to CLIA regulation. If the test is performed by using commercially prepared and purchased active ingredients (so-called analytic specific reagents or ASRs), FDA does impose requirements on both the... 

Single-site IVD "Home brew" or "in-house" IVD made with an analyte specific reagent FDA requires labeling disclosing the "in-house" nature of the test but has no premarket review requirement CLIA requires analytical validation and quality control systems... 

Commercial reagents for use in "home brew" tests Analyte specific reagents FDA most 510(k) exempt blood bank and high-public health-risk reagents subject to premarket reviews CLIA oversight of laboratories using these reagents... 

Department of Health and Human Services, Food and Drug Administration. Medical devices classification/reclassification restricted devices analyte specific reagents. Final rule. Fed Register. 1997(Nov 21) 62243-45 [21CFR809, 21CFR864] http //www.fda.gov/cdrh/oivd/index.html (accessed August 19,2004). 

Graziano C. Disclaimer now needed for analyte-specific reagents. CAP Today 1998 12 5-11. 

Abundance-based (analytical) microarrays, which seek to measure the abundance of specific biomolecules (e.g. proteins) using analyte-specific reagents such as monoclonal antibodies. For this purpose, capture microarrays are generated by spotting specific capture... 

The differentiation of analytical signal in the photometry enables one to use non-specific reagents for the sensitive, selective and express determination of metals in the form of their intensively coloured complexes. The typical representative of such reagents is 4-(2-pyridylazo)-resorcinol (PAR). We have developed the methodics for the determination of some metals in the drinking water which employ the PAR as the photometric reagent and the differentiation of optical density of the mixture of coloured complexes by means of combined multiwave photometry and the specific destmction of the complexes caused by the change of the reaction medium. 

If there is any doubt as to the purity of the reagents used, they should be tested by standard methods for the impurities that might cause errors in the determinations. It may be mentioned that not all chemicals employed in quantitative analysis are available in the form of analytical reagents the purest commercially available products should, if necessary, be purified by known methods see below. The exact mode of drying, if required, will vary with the reagent details are given for specific reagents in the text. 

Unlike 2-thiazolidinethione and its simpler derivatives, the 3 - alkyl - 5 - hydroxy - 5 - (1,2,3,4 - tetrahydroxy -n- butyl) - 2 - thiazoli-dine thiones [which are specific, photometric reagents for Cu(ID] undergo rearrangement in the presence of Cu(II) ions, to form complexes of dithiocarbamate. The analytical specificity is explained by the inability of most other metal ions to effect this rearrangement (419). 

On the other hand, specificity refers to single component analysis and means that the one individual analyte can be undisturbedly measured in a real sample by a specific reagent, a particular sensor or a comparable measuring system (e.g., measurement of emitted or absorbed radiation at a fixed wavelength). 

The RPIA technology has been enhanced in the Stratus CS system by utilization of a dendrimer-antibody complex in which the analyte-specific capture antibody is covalenty coupled onto a dendrimer. The test packs in the Stratus CS system include dendrimer-capture antibody complex reagent, the alkaline phosphatase labeled antibody conjugate reagent, the substrate-wash reagent and a piece of glass fiber filter paper as the solid phase. Preparation and unique properties associated with these dendrimer-coupled antibody complexes are described below. 

The development of techniques for the production of monoclonal antibodies by Kohler and Milstein has enormously expanded the potential of antibodies as analytical and therapeutic agents. A monoclonal antibody is one that is produced by a clone of cells all derived from a single lymphocyte. Any lymphocyte can probably produce only a single immunoglobulin and hence the antibody produced by a clone of identical cells is very restricted in the antigens to which it will bind, making it a very specific reagent. 

Difficulties are encountered in the qualitative and quantitative analysis of carbohydrate mixtures because of the structural and chemical similarity of many of these compounds, particularly with respect to the stereoisomers of a particular carbohydrate. As a consequence, many chemical methods of analysis are unable to differentiate between different carbohydrates. Analytical specificity may be improved by the preliminary separation of the components of the mixture using a chromatographic technique prior to quantitation and techniques such as gas-liquid and liquid chromatography are particularly useful. However, the availability of purified preparations of many enzymes primarily involved in carbohydrate metabolism has resulted in the development of many relatively simple methods of analysis which have the required specificity and high sensitivity and use less toxic reagents. 

The use of liquid membranes in analytical applications has increased in the last 20 years. As is described extensively elsewhere (Chapter 15), a liquid membrane consists of a water-immiscible organic solvent that includes a solvent extraction extractant, often with a diluent and phase modifier, impregnated in a microporous hydrophobic polymeric support and placed between two aqueous phases. One of these aqueous phases (donor phase) contains the analyte to be transported through the membrane to the second (acceptor) phase. The possibility of incorporating different specific reagents in the liquid membranes allows the separation of the analyte from the matrix to be improved and thus to achieve higher selectivity. 

The reaction of aqneons green Np, or its bine ammonia complex, with colorless dimethylglyoxime (DMG) to form a vibrantly red precipitate of a 1 2 metaLDMG complex demonstrates an example of precise stereochemistry and oxime deprotonation in what is perhaps the archetypal analytical metal dioxime reaction (equation 1). This transformation certainly intrigued both authors early in their education. It is interesting to note that DMG is an excellent example of highly specific reagent because under the same reaction conditions only yellow palladium chelate is also precipitated. 

The sensitivity and simplicity of an analytical method always improves when selective detection can be used. Because of detection selectivity, a sample in a complex matrix can be analysed with minimum sample preparation. Wouldn t it be ideal to have an ultra-specific reagent that would allow the determination of a compound in an environment containing thousands of substances ... 

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