ANALYTICAL ELEMENT AND METHOD FOR THEOPHYLLINE DETERMINATION HAVING INCREASED ALKALINE PHOSPHATASE ISOENZYME

• Main Authors: NORTON, GARY E, FRICKEY, PAUL H
• Format: Patent
• Language: English; French
• Published: 15.10.1991
• Edition: 5
• Subjects: BEER; BIOCHEMISTRY; CHEMISTRY; COMPOSITIONS OR TEST PAPERS THEREFOR; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL ORENZYMOLOGICAL PROCESSES; ENZYMOLOGY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEICACIDS OR MICROORGANISMS; METALLURGY; MICROBIOLOGY; MUTATION OR GENETIC ENGINEERING; PHYSICS; PROCESSES OF PREPARING SUCH COMPOSITIONS; SPIRITS; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS; TESTING; VINEGAR; WINE

IMPROVED ANALYTICAL ELEMENT AND METHOD FOR THEOPHYLLINE DETERMINATION HAVING INCREASED ALKALINE PHOSPHATASE ISOENZYME Theophylline can be determined with an analytical element and method which utilize the inhibition, by theophylline, of alkaline phosphatase activity on an appropriate substrate. The assay is carried out at a pH of 9 or less. The element comprises an absorbent carrier material, a suitable buffer and first and second zones in fluid contact. The isoenzyme of alkaline phosphatase and a suitable substrate for the isoenzyme are located in different zones of the element. The isoenzyme is present in one of the zones in an amount of at least about 100 I.U./m2. This level of isoenzyme reduces or eliminates bias caused by endogenous alkaline phosphatase and hemoglobin during an assay.