Patent · US Expired

Apparatus and method for biological analysis

US3930957A · kind A · utility

8Cited by
4References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 11, 1974
Grant dateJan 6, 1976
Priority date
Expiry dateJul 11, 1994

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N33/5308
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A continuous method and apparatus for the determination of urea in a biological fluid such as blood, for example, is disclosed. In a continuously flowing system, the biological sample is introduced into a buffered carrier solution of low electrical conductance and is caused to flow into a chamber containing an immobilized enzyme which catalyzes a specific reaction which changes the electrical properties of the solution by increasing the dissociated ion concentration therein. This increase in dissociated ion concentration is directly proportional to the original concentration of urea in the biological sample; and any one of the several conventional electrical measurements may be made to determine the increase in such concentration or the rate of increase in such concentration and thereby determine the concentration of urea in the original biological sample. The buffered carrier solution containing the products of the enzyme-catalyzed reaction is reclaimed by circulating it through a deionization, purification stage in which the solution conductivity is substantially returned to the prereaction value. The carrier solution is recirculated and used for processing additional samples. Th…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.