Immobilized Enzymes in Continuous-FlowAnalysis

Glucose oxidase, uricase, and urease were immobilized on the interior surface of activated polyamide tubing. The shelf-life of such enzyme-bearing tubes was at least six months. The tubes were used for continuous-flow analysis of glucose, uric acid, and urea with conventional systems and with hybrid micro-scale systems in which modules of different manufacture were combined. The length of en-zyme-bearing tube required for each system was ascer-tained empirically. Each tube could be used for several thousand assays, but glucose oxidase-bearing tubes were more stable than urease- or uricase-bearing tubes. Results for patients ’ samples correlated well with results obtained by accepted methods. AddItional Keyphrases: enzyme bonding to polyamkie enzyme activity. enzyme stability. glucose oxidase unease unease enzymatic methods of analysis. glu-cose assay ‘ uric acid assay urea assay. micro-scale assays Assays based on enzymatic conversion of the analyte can offer great specificity. Unfortunately, the widespread use of such methods may he precluded when enzyme purification is expensive or when large amounts of enzyme are necessary, as in continuous-flow analysis. Both of these constraints can he overcome by immobilizing the enzyme on a surface that is part of the how system. We bonded glucose oxidase, uricase, and urease to the in-ternal surface of specific types of polyamide tubing. With such enzyme-bearing tubes many assays can be performed with conventional continuous-flow systems or hybrid micro-scale systems while requiring insignificant amounts of enzyme