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:
Nov. 16, 2004
Filed:
Jun. 22, 2001
Vincent Chiang, Sunnyvale, CA (US);
Abaxis, Inc., Union City, CA (US);
Abstract
Chloride ion and sodium ion determination methods, compositions, and assays are provided which are based on the use of sodium ion as an activator for &agr;-amylase. Chloride ion and sodium ion determination are performed by colorimetry, using measurements of &agr;-amylase activity to indirectly measure the desired ion concentrations. One preferred composition for chloride ion determination comprises &agr;-amylase that is substantially calcium free, sodium ion in higher concentration than the &agr;-amylase, and an &agr;-amylase activity detecting substrate. In the methods, &agr;-amylase is deactivated by a calcium-binding compound, thereby preventing calcium from bonding with the &agr;-amylase. Next, chloride ion and sodium ion stoichiometrically bond with deactivated &agr;-amylase, thereby activating the &agr;-amylase. Chloride ion determination methods are based on using test sample chloride as the limiting factor in &agr;-amylase activation and sodium ion determination methods are based on using test sample sodium as the limiting factor in &agr;-amylase activation.