Specimens for test substances that exhibit diurnal variation must be collected:

Question

Quizplus · Accepted Answer

Specimens for test substances that exhibit diurnal variation must be collected at specific times to ensure consistency in results. This is because the levels of these substances can vary throughout the day, depending on the body's natural rhythms. Therefore, it is important to collect specimens at the same time of day to ensure accurate and reliable results. Fasting, lying down, and basal state may be important factors for other types of tests, but do not specifically address the issue of diurnal variation.

Specimens for Test Substances That Exhibit Diurnal Variation Must Be