Enzymatic analysis clinical applications

Amino acid analysis is widely applied in research, clinical facilities, and industry. It is a fundamental technique in biotechnology, used to determine the concentration of peptide solutions, to confirm protein binding in antibody conjugates, and for end-terminal analysis following enzymatic digestion. Clinical applications include diagnosing metabolic disorders in newborns. In industry, it is used for quality control of products ranging from animal feed to infant formula. 

Flow injection analysis has also found numerous applications in the analysis of clinical samples, using both enzymatic and nonenzymatic methods. A list of selected examples is given in Table 13.3. 

The POCL reaction has been used for trace determinations of hydrogen peroxide, most commonly in environmental and clinical analysis [26-52], The latter applications often include various enzyme systems [34-52], where a number of substrates can be indirectly determined by measuring the hydrogen peroxide that is produced as a by-product in the enzymatic reaction. 

A systematic description of the scope of fluorescence spectroscopy in clinical and drug analysis is rendered difficult by the very large number of determinations reported so far. For reasons of space, this article can only present an overview of the wide variety of applications of this technique in these analytical fields, such as chromatographic and electrophoretic methods, its use in enzymatic and immunochemical assays and in biosensors, and its usefulness in new research areas such as proteomic studies. 

Although kinetic methods of analysis are of special significance to clinical and pharmaceutical analysis in relation to enzymatic methods, they are equally applicable to nonenzymatic processes. Table 7 shows the most salient contributions reported in this respect over the past few years. Most of the clinical determinations shown have been performed on blood and/or urine samples and have involved inorganic or organic ions in similar proportions. On the other hand, pharmaceutical determinations have chiefly been concerned with organic substances. The Sandell-Kolthoff reaction has by far been the most commonly employed for the analysis of biological samples, so much... 

The NADH produced is subsequently measured by spectrophoto-metric or fluorimetric detection. The characteristics of the main enzymatic assays are reported in Table 3. The first application of this prin ple to serum 3o(-hydroxy bile acids was reported by Iwata et al. in 1964. Using spectrophotometric determination of NADH at 340 nm, they found the lowest practical limit of detection to be approximately 0.01 j Amol in the final reaction mixture (3 ml). This implied that at least 20 ml of serum were needed for the analysis, introducing a high background and clinical imprati-cability. 

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