Radio-immuno assay

Use of a surrogate end point that is quick and easy to obtain Permeation experiments using a radiolabeled, fluorescent, HPLC-detectable, or radio immuno assay/enzyme linked immuno sorbent assay-detectable marker necessitate the need of extensive sample handling and sample analysis. This accentuates the cost of sample analysis and overall time spent in characterizing the efficacy of formulations. Furthermore, current state of the art fluidics systems put a fundamental limit on the number of samples handled in a given time. 

Of the other established methods one can be less certain. Electrochemical methods, other than ion selective electrodes, seem to be practised more in academic laboratories than industrial, and are prone to fundamental problems relating to electrode contamination and chemical interferences. Nuclear methods would seem to have reached their apogee (if one classifies radio immuno assay as biological rather than nuclear) and the same seems to be true of thermal methods. This is not to say that these methods will not continue to be used and to be important. It is a comment that despite the missionary work of numerous adherents of these methods, one notes in the large industrial laboratories much more application of and enthusiasm for spectroscopy, chromatography and biological methods. 

Formula and data, see morphinan alkaloids. M. is the most important morphine (opium) alkaloid. M. is poorly soluble in boiling water and chloroform, soluble in alcohol, aqueous calcium and magnesium hydroxides and phenol. M. is obtained by extraction from the poppy Papaver somniferum. M. can be detected by sever color reactions (e. g. violet color with Fe in alkaline solution), particularly sensitive procedures are gas chromatography, mass spectroscopy, and radio-immuno assays. 

The plasma testosterone level of males was associated with the attractiveness of male odors to females. Plasma testosterone level was determined using radio-immuno assays (Diagnostic Products Inc., CA). A blood sample was taken from the infra-orbital si-... 

Many assays are available to measure lipid peroxidation, but no single assay is an accurate measure of the whole process (70). The assay used by Basu et al. (64) and Riserus et al. (35), a radio-immuno assay of urinary 15-keto-dihydro-prostaglandin F2a and of 8-iso-prostaglandin F2a formation, has not been widely used. This complicates the interpretation of the relevance of the results. Markers of inflammation, such as IL-6, a - and y-tocopherol and TNFa were not affected in the study by Riserus et al. (34, 35), indicating that CLA did not induce inflammation. 

It would be an advantage if drugs and/or their metabolites in biological samples (blood, urine, feces, bile, tissues) could be analyzed directly. However, this has only been achieved with radio immuno assay (RIA) procedures and, in some cases, with voltammetric methods, but with high detectability limits (20 ug/ml). In all other cases background... 

Table 3 Examples of radio immuno-like assays ...

Laboratory diagnosis of Chagas disease is complex, primarily because of the genetically diverse and polymorphous parasite. PCR is not always able to detect the specific DNA because of intermittent or low levels of parasites in the blood stream during the chronic stage. Radio-immuno-precipitation assay (RIPA), a highly specific test with easily interpreted results, has been a confirmatory test used in the... 

Cells were treated in T75 flasks and lysed in radio-immuno-precipitation assay (RIPA) buffer (50 mM Tiis-HCl, pH 7.6, 150 mM NaCl, 1% Nonidet P-40, 0.1% SDS, 0.5% sodium deoxycholate, 2 mM EDTA, protease inhibitor complete minitab and 10 mM sodium orthovanadate). 500 pg of homogenate was incubated with 5 pg anti-Ret antibodies in TBS-T buffer (20 mM Tri HCl, pH 7.6, 137 mM NaCl, and 0.1% Tween 20) overnight at 4°C, followed by 2 h incubation with Protein G agarose. Samples were separated on an SDS-PAGE gel for Western blot analysis with anti-pTyr and anti-Ret antibodies. 

One prominent use of organometallic complexes is in metallo-immuno assays. The traditional radio-linked immuno assay (RIA) is highly sensitive but has obvious disadvantages related to the use of radioactivity. Modern alternatives use colorimetric, fluorescence, or enzyme-linked detection schemes (ELISA). The idea of using non-radioactive metals for specific, highly sensitive detection in immuno assays was first mentioned by Gais, who used steroid... 

A radioisotope can be used as a tracer instead of the enzyme used in immunochemical tests. This method, introduced in 1960 for the measurement of insulin in serum, is called radio-immunology. It is the transposition in immuno-chemistry of the same principle as that used to determine the sulphate ion (cf. 17.5). Radioimmunoassays are similar to ELISA assays in the way in which the analysis is... 

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