| Abstract: | Clinical chemistry is concerned with the measurement of substances in biological matter, predominantly blood, serum or plasma. Significant, though small, changes may take place as a prelude to a life-threatening situation. Therefore analytical techniques in clinical chemistry must be sensitive, specific and rapid. Many features of an enzyme-catalysed reaction are incorporated in the design of diagnostic reagents. The specificity of an enzyme may be employed to measure a substrate, or to remove interferents in another reaction. The measurement of substances that act as cofactors, inhibitors or activators can be achieved by the use of the appropriate enzyme. Finally, the enzyme, as a catalyst, can be used as a label in various immunoassay techniques. Clinical chemistry tests are carried out in a wide variety of environments, from the large laboratory undertaking many hundreds of analyses down to a clinic performing only a few tests. Enzymes are therefore employed in analytical systems based on widely differing presentations. Thus enzymes may be employed in a solution medium, immobilized on a surface of the reaction vessel or in a reagent strip. The requirements imposed on the reagent enzyme may be different in all of these situations. |
