Antiglycolytic agents are used if three tests are done in more than how many hours?

• A. 1 hour
• B. 2 hours
• C. 4 hours
• D. 8 hours

Answer: (A)

Glycolysis continues after blood is drawn, so glucose levels can fall if the sample isn’t tested promptly. Antiglycolytic agents, such as sodium fluoride in fluoride-oxalate tubes, slow or stop this glycolysis to keep the glucose value accurate for later testing.

When multiple tests are planned on a single sample, delays before all tests are completed can lead to artifactual glucose loss. If the testing will take longer than about one hour, adding the antiglycolytic agent helps preserve the glucose concentration for the entire set of analyses. Therefore, the need for antiglycolytic agents arises when a delay exceeds one hour. The other time options imply longer delays where glycolysis would progress more, but the standard precaution is to use the agent if the planned testing will take more than one hour.