Radioimmunoassay technique

In this one reaction both PQ and P Q are generated simultaneously. These complexes can be referred to as either the bound fraction of P or P. However in radioassay and radioimmunoassay techniques, the concern is with the bound fraction of P (i.e., P Q), since it is this complex that is measured. 

The radioimmunoassay technique has been gainfully exploited in a variety of novel applications of which only the two important aspects stated below will be discussed briefly, namely ... 

Yang S. and K. Carlson (2004). Routine monitoring of antibiotics in water and wastewater with a radioimmunoassay technique. Water Research 38 3155-3166. 

This research will determine the suitability of radioimmunoassay techniques for such tests and will establish experimental limits for making sexual determinations based on the ratio of testosterone and estradiol in a bloodstain. 

Radioimmunoassay techniques may aid in clarifying genetic relationships if sufficient immunological activity is maintained in archaeological bones, In Chapter 22, Herr, Benjamin, and Woodward discuss some new immunological tests that can distinguish between blood and tissue of human... 

The traditional radioimmunoassay technique could be utilized with rare earth phosphate NPs. Lin et al. reported the LuP04-apoferritin coreshell NPs synthesized in apoferritin templates. The NPs were further modified with biotin and exhibited affinity for streptavidin-modifed magnetic beads or streptavidin-modifed fluorescein isothiocyanate. Radioactive Lu was used to label the NPs (Wu et al., 2008a). 

Protein A, a structural component of certain strains of staphylococci, has been used successfully in the place of the second antibody in radioimmunoassay techniques, as well as the solid phase adsorbent of antibody (mentioned in the section Solid Phase Materials). This protein can be heavily labeled with and is, therefore, a reasonable alternative for the use of labeled antiglobulins in immunoassays. 

Radiochemical methods of analysis are considerably more sensitive than other chemical methods. Most spectral methods can quantitate at the parts-per-mil-lion (ppm) level, whereas atomic absorption and some HPLC methods with UV, fluorescence, and electrochemical methods can quantitate at the parts-per-billion (ppb) levels. By controlling the specific activity levels, it is possible to attain quantitation levels lower than ppb levels of elements by radiochemical analyses. Radiochemical analysis, inmost cases, can be done without separation of the analyte. Radionuclides are identified based on the characteristic decay and the energy of the particles as described in detection procedures presented above. Radiochemical methods of analysis include tracer methods, activation analysis, and radioimmunoassay techniques. 

Hypocalcemic perfusion of the pig thyroid in situ results in a slight rise in the systemic blood calcium level, which might be caused by a shutting-off of thyrocalcitonin secretion (C5). The normal level of thyrocalcitonin output might depend on the prevailing level of secretion of parathyroid hormone this possibility is supported by the observation that hypocalcemic perfusion of the thyroid in parathyroidectomized pigs was unaccompanied by the rise in systemic plasma calcium observed in intact animals. Until sensitive immunoassay procedures become more widely available, however, it is difficult to be sure whether or not thyrocalcitonin is secreted under resting conditions in the intact animal. A preliminary report of a radioimmunoassay technique for thyrocalcitonin, by Arnaud and Littledyke (A5), indicates that all plasma samples examined contained detectable thyrocalcitonin, and that thyroidectomy resulted in a decrease in thyrocalcitonin levels below those found in normal animals. 

Relatively new but quickly adopted and developed analytical methods for barbiturates are the enzyme and radioimmunoassay techniques.497 The principles and procedures have been reviewed498-502 and comparisons between these and other analytical methods are available.233,503-512... 

Little is known about the synthesis of TSH. Direct measurement of serum TSH by radioimmunoassay techniques (R6, Ul) or in vitro or in vivo bioassays (A3, K3) showed that TSH in blood decreased when thyroid hormone was given to hypothyroid persons. Free thyroxine levels were more directly related to the changes in TSH concentration (R6). The half-life of TSH in blood as measured by the use of I-labeled h-TSH is about 30-60 minutes (02, 03). 

If the feedback hypothesis of thyroid hormone regulation is correct, TSH levels in the blood of hypothyroid people should be increased. Several reports (Table 1) confirm this, including reports based on studies using radioimmunoassay techniques. TSH levels decline when patients are treated by thyroid hormone replacement (02). This does not apply when the hypothyroidism is secondary to pituitary dysfunction. 

ME Alburges, et al. Evaluation of a radioreceptor assay to measure fentanyl and fentanyl-like drugs using gas chromatography/mass spectrometry and radioimmunoassay techniques. FASEB J 2 1807, 1988. 

An analogous method uses the enzyme AMP-transferase, which adenylates hydroxy groups of the aminoglycosides in the presence of C-ATP or Radioimmunoassay techniques are also useful for the quantitative determination of amino ycosides ... 

There are several different techniques employed for the detection of OPC, including conventional analytical methods enzyme, hnorescence, and radioimmunoassay techniques immunochemical methods some biosensor technology, which includes optical, piezoelectric, electrochemical, microhuidic, and array-based (Lab-on-a-chip) biosensors. These techniques are described later in this chapter. 

The most widely applied procedure is a radioimmunoassay technique, developed by Wide et al. (1967) and now commercially available (RIST-Pharmacia, Upp-... 

Considerable attention has been paid recently to the development of radioimmunoassay techniques for detecting serum levels of glycosides and this has led to valuable information on the antigenicity of individual members of the series. 

Administration of high doses of capsaicin to the rat by the subcutaneous route was the first procedure by which an effect on spinal cord substance P was found. It is noteworthy that this work, conducted by Gasparovic et al. (1964), preceded by many years the current surge of interest in capsaicin. Using a bioassay for substance P, they showed that capsaicin reduced the content of this peptide in whole spinal cord but did not alter that of whole brain. This has recently been confirmed by Jessell et al. (1978) who, using radioimmunoassay techniques, found a 48% reduction in the levels of spinal cord dorsal horn substance P. Similar results have since been obtained by Gamse et al. (1980a,fe). In addition they reported reduced substance P content of dorsal roots, dorsal root... 

B. Serum determinations The following serum determinations should be performed by radioimmunoassay techniques using National Institutes of Health (NIH) specific antigen or antigen preparations of equivalent sensitivity ... 

Similar principles may be used for the assay of many other hormones. The radioimmunoassay technique is widely used in research into the mechanism of hormone synthesis and secretion, and is also used to determine the concentration of hormones in plasma in normal and pathogenic conditions. 

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