The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 06, 1994
Filed:
Dec. 10, 1993
Applicant:
Inventors:
Thomas N Stewart, Durham, NC (US);
Glenn P Vonk, Fuquay-Varina, NC (US);
James P Mapes, Raleigh, NC (US);
Assignee:
Becton, Dickinson and Company, Franklin Lakes, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C12Q / ; G01N / ;
U.S. Cl.
CPC ...
435 12 ; 422 56 ; 422 57 ; 435-791 ; 435805 ; 435970 ; 436904 ;
Abstract
A method for detecting urea in a liquid sample in which urease is adsorbed on a solid support such as a membrane and contacted with a solution suspected of containing urea, a pH-dependent reducing agent and a tetrazolium salt. When urea is present in the solution, the adsorbed urease converts it to ammonia, thus raising the pH and causing the pH-dependent reducing agent to reduce the tetrazolium salt to an insoluble colored formazan. The formazan precipitates as a detectable spot on the solid support, indicating the presence of urea in the liquid sample.