A practice-oriented guide to assaying more than 100 of the most important enzymes, complete with the theoretical background and specific protocols for immediate use in the biochemical laboratory. Now expanded with a new section on metal ion determination.

Enzyme assays are among the most frequently performed procedures in biochemistry and are routinely used to estimate the amount of enzyme present in a cell or tissue, to follow the purification of an enzyme, or to determine the kinetic parameters of a system. The range of techniques used tomeasure the rate of an enzyme-catalysed reaction is limited only by the nature of the chemical change and the ingenuity of the investigator. This book describes the design and execution of enzyme assays, covering both general principles and specific chapters.Building upon the highly popular first edition, this book combines revised or rewritten chapters with entirely new contributions. Topics include experimental protocols covering photometric, radiometric, HPLC, and electrochemical assays, along with methods for determining enzyme assays after gelelectrophoresis. The theory underlying each method is outlined, together with a description of the instrumentation, sensitivity and sources of error. Also included are chapters on the principles of enzyme assay and kinetic studies; techniques for enzyme extraction; high- throughout screening;statistical analysis of enzyme kinetic data; and the determination of active site concentration.This second edition of Enzyme Assays will be valuable not only to biochemists, but to researchers in all areas of the life sciences.

This report documents work at the U.S. Geological Sur- vey (USGS) National Water Quality Laboratory (NWQL) to validate enzymatic reduction, colorimetric determinative meth- ods for nitrate + nitrite in filtered water by automated discrete analysis. In these standard- and low-level methods (USGS I-2547-11 and I-2548-11), nitrate is reduced to nitrite with nontoxic, soluble nitrate reductase rather than toxic, granular, copperized cadmium used in the longstanding USGS auto- mated continuous-flow analyzer methods I-2545-90 (NWQL laboratory code 1975) and I-2546-91 (NWQL laboratory code 1979). Colorimetric reagents used to determine resulting nitrite in aforementioned enzymatic- and cadmium-reduction meth- ods are identical. The enzyme used in these discrete analyzer methods, designated AtNaR2 by its manufacturer, is produced by recombinant expression of the nitrate reductase gene from wall cress (Arabidopsis thaliana) in the yeast Pichia pastoris. Unlike other commercially available nitrate reductases we evaluated, AtNaR2 maintains high activity at 37°C and is not inhibited by high-phenolic-content humic acids at reaction temperatures in the range of 20°C to 37°C. These previously unrecognized AtNaR2 characteristics are essential for success- ful performance of discrete analyzer nitrate + nitrite assays (henceforth, DA-AtNaR2) described here.

"Blood transfusion is a life-saving intervention that has an essential role in patient management within health care systems. All Member States of the World Health Organization (WHO) endorsed World Health Assembly resolutions WHA28.72 (1) in 1975 and WHA58.13 (2) in 2005. These commit them to the provision of adequate supplies of safe blood and blood products that are accessible to all patients who require transfusion either to save their lives or promote their continuing or improving health." --Preface.