Immobilized-enzyme nylon-tube reactor for routine determination of uric acid in serum

We report here the preparation of an immobilized-enzyme nylon-tube reactor containing uricase (EC 1.7.3.3) and the assembly of a flow-through system (Technicon AutoAnalyzer II) for the routine determination of uric acid in serum. Results of these uric acid analyses by use of immobilized uricase, in conjunction with peroxidase (EC 1.11.1.7) and aminophenazone-dichlorophenol in solution, are compared with those obtained with the same enzyme in solution by use of the uricase-PAP (peroxidase, 4-aminophenazone, dichlorophenol) method. Clinical trials carried out routinely with the uricase reactor give reliable and reproducible results with high precision at an appreciably lower cost. The reactors are stable to continued or intermittent use for at least three months or for 4000 tests.