Related Experiment Video
Updated: Aug 15, 2026

Determination of Microbial Extracellular Enzyme Activity in Waters, Soils, and Sediments using High Throughput Microplate Assays
Published on: October 1, 2013
Demographic and analytic factors affecting the normal range of serum enzyme activities
Abstract:
1. The effect of demographic variables such as age, sex, body weight, social class and blood pressure upon the activity of serum enzymes in healthy humans is reviewed. A system developed by the author and his colleagues, which automatically adjusts the results of enzyme activity measurements to allow for demographic influences, is described. This allows derivation of a "demographically corrected" normal range; for most enzymes this range is much narrower than that provided by the conventional mean +/- 2 SD approach. 2. The influence of precision and analytical factors upon the normal range for serum enzymes is discussed. Data from a British national quality-control survey reveal a depressing picture of interlaboratory precision for commonly determined enzyme estimations. Examples are given (serum aspartate aminotransferase and guanase) which illustrate the influence that precision of a method may have on the normal range for that enzyme.
Related Concept Videos
Enzyme Kinetics
Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. When more reactant, or substrate, is...
Introduction to Mechanisms of Enzyme Catalysis
Factors Affecting Protein-Drug Binding: Patient-Related Factors
Age stands as a key determinant in protein-drug binding. Neonates, characterized by low albumin content, experience heightened concentrations of unbound drugs such as phenytoin and...
Therapeutic Drug Monitoring: Affecting Factors
Effect of Hepatic Disease on Pharmacokinetics: Pathophysiologic Assessment and Liver Function Test
Serum Studies: Renal Function Tests

