Accession Number:

AD0787314

Title:

Influence of Temperature on the Delta pH Method of Measuring Blood Cholinesterase.

Descriptive Note:

Technical rept. Sep 73-Feb 74,

Corporate Author:

EDGEWOOD ARSENAL ABERDEEN PROVING GROUND MD

Personal Author(s):

Report Date:

1974-09-01

Pagination or Media Count:

11.0

Abstract:

Efforts to evaluate the precision of the Michel delta pH method of measuring cholinesterase activity, performed in a breaker immersed in a 25C water bath, resulted in unexpected variability in results of day-to-day replicate analyses. Most disturbing was the considerable variation between each 4-hour period of an 8-hour day a.m. and p.m. measurements. Precision of quadruplicate sets, expressed as coefficient of variation, ranged from plus or minus 0.5 to 8.0. By rigidly controlling temperature with a water-jacketed reaction vessel, the variation was reduced to plus or minus 1.7. A study of the effect of temperature on the method showed that a 1-degree change in temperature resulted in a 5.5 change in plasma activity and a 3.0 change in red cell activity. A graphing of the influence of temperature on reaction rate produced a linear relationship. Identical thermodynamic data were obtained with plasma and red cell samples which were inhibited 50 with an with an irreversible anticholinesterase agent. Author

Subject Categories:

  • Biochemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE