Without fluoride, glucose will decrease in concentration by what percentage within a single hour?

Without fluoride, glucose will decrease in concentration by what percentage within a single hour?

• A. 3-5
• B. 15-20
• C. 0-2
• D. 7-10

Answer: (D)

The key idea is that glucose in a drawn blood sample keeps being used by cells through glycolysis, so its concentration drops unless a glycolysis inhibitor is present. Sodium fluoride is used in certain collection tubes to block glycolysis and preserve glucose levels. Without fluoride, the glucose concentration typically falls by about 7–10 percent in one hour at room temperature. So, starting from 100 mg/dL, you’d expect roughly a 7–10 mg/dL decrease after an hour. This aligns with the option reflecting a 7–10% drop.

The key idea is that glucose in a drawn blood sample keeps being used by cells through glycolysis, so its concentration drops unless a glycolysis inhibitor is present. Sodium fluoride is used in certain collection tubes to block glycolysis and preserve glucose levels. Without fluoride, the glucose concentration typically falls by about 7–10 percent in one hour at room temperature. So, starting from 100 mg/dL, you’d expect roughly a 7–10 mg/dL decrease after an hour. This aligns with the option reflecting a 7–10% drop.