Related Experiment Video
Updated: Oct 10, 2026

A Method for Manipulating Blood Glucose and Measuring Resulting Changes in Cognitive Accessibility of Target Stimuli
Published on: August 12, 2016
Effects of transportation and delay in processing on the stability of nutritional and metabolic biomarkers
J M Murphy1, R W Browne, L Hill
1Department of Social and Preventive Medicine, State University of New York at Buffalo, Buffalo, NY 14214, USA.
Abstract:
The effects of transportation and delay in processing of blood samples on the concentration of biomarkers are significant in epidemiological studies for which specimens are collected from participants at locations other than a designated center or laboratory. These sources of variability in measurement were studied by collecting two sets of blood samples from 51 men between 26 and 50 years of age. The first set was sent immediately to the laboratory for processing. The second set was transported by car for one hour and then returned to the laboratory for processing. Both sets were stored together at -80 degrees C until the end of the study. Several blood constituents were evaluated. Vitamins, liver enzymes, and electrolytes showed no changes in concentration after transport by car for one hour. There were decreases in the concentrations of red and white blood cells, high-density-lipoprotein cholesterol, glucose, and creatinine after transportation. The transported total cholesterol, total testosterone, free testosterone, alkaline phosphatase, total bilirubin, and thiobarbituric acid-reactive substances increased in concentration. Although transportation and delay in processing of blood samples do not appear to greatly impact relative risk estimates, epidemiologists should be aware of these potential sources of variability in measurement and consider the consequences in their particular study.
Related Concept Videos
Factors Affecting Drug Biotransformation: Biological
Species differences: Variations in enzyme systems across species can cause disparities in drug metabolism. For instance, humans may metabolize certain drugs faster than rodents, altering therapeutic effects.
Strain differences: Genetic variations within a species can result in differing enzyme activity, impacting drug response and toxicity. For example, some mouse strains may...
Noncompartmental Analysis: Mean Transit, Absorption and Dissolution Time
One of the key parameters is the mean transit time (MTT), which refers to the total duration required for drug molecules to transit through the body. MTT is determined by calculating the ratio of the area under the moment curve to the area...
Bioavailability Enhancement: Drug Stability Enhancement and GI Retention
Effect of Hepatic Disease on Pharmacokinetics: Pathophysiologic Assessment and Liver Function Test
Pharmacokinetics in Obese Patients: Drug Metabolism and Excretion
Nonlinear Pharmacokinetics: Role of Transporters
Polymorphisms occurring in drug transporters can alter...