Which statement best describes the reason for immediate processing of CSF glucose samples?

• A. To prevent glycolysis from lowering glucose
• B. To avoid contamination by bacteria
• C. To preserve protein levels
• D. To maintain pH

Answer: (A)

Glucose in CSF can be consumed by cells and any bacteria present after collection. If the sample sits around, glycolysis continues in the specimen, lowering the measured glucose value and giving a falsely “low” result. Processing the sample immediately (or cooling/inhibiting glycolysis) stops this in vitro metabolism and preserves the true glucose concentration as it was in vivo. The other factors—contamination, protein preservation, or pH maintenance—don’t directly address this in vitro glycolytic loss, so preventing glycolysis is the key reason for immediate processing.