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

Abstract

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.

Immobilized-enzyme pipette. Scope and limitations of a simple device

“…diam. 1 mm) was supplied by Portex Ltd., Hythe, Kent, U.K. Urease type III (28 units/mg) was obtained from Sigma Chemical Co., St. Louis, MO, U.S.A. All other chemicals were obtained from Aldrich Chemical Co., Mil-waukee, WI, U.S.A. Disposable pipette tips containing immobilized enzyme may be prepared by coupling the enzyme directly to activated nylon tubes as described by Sundaram et al (1978b). Coiled tubing was filled with 0.1 M-triethyloxonium tetrafluoroborate made up in dichloromethane and allowed to react for 4min at room temperature.…”