A chemiluminometric method for the determination of urea in serum using a three-enzyme bioreactor

✍ Scribed by Tabata, Masayoshi ;Murachi, Takashi

• Publisher: John Wiley and Sons
• Year: 1988
• Weight: 369 KB
• Volume: 2
• Category: Article
• ISSN: 0884-3996
• DOI: 10.1002/bio.1170020202

✦ Synopsis

A flow injection chemiluminometric assay for urea has been developed based on a minicolumn bioreactor packed with immobilized enzyme-bearing glass beads. The reactor contains immobilized urease, L-glutamate dehydrogenase and L-glutamate oxidase, aligned in this order (upstream t o the downstream). When the sample is introduced into the bioreactor, urea is first hydrolysed by urease t o produce ammonia, which is then converted into L-glutamate by L-glutamate dehydrogenase. L-Glutamate is finally oxidized by L-glutamate oxidase t o produce hydrogen peroxide, which is quantified by measuring chemiluminescence emitted upon admixing with luminol and potassium ferricyanide. One assay cycle is completed within 1 minute. The method is sensitive (detection limit 0.5 nmol) and is linear in the range 0 3 0 mmol/l. It can be readily applied t o the determination of urea in human serum, and requires no blank corrections for ammonia and/or L-glutamate present in serum samples.