Which sample tube should be used for routine glucose determination?

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Analytical Biochemistry

Background:

• Accurate blood glucose measurement is vital in clinical diagnostics.
• In vitro glycolysis in collected blood samples can lead to inaccurate glucose readings.
• Evaluating different blood collection tubes is necessary to mitigate pre-analytical errors.

Purpose of the Study:

• To compare the suitability of various blood collection tubes for glucose analysis.
• To assess the impact of delayed plasma separation on glucose stability at room temperature.
• To identify the optimal tube for preserving glucose integrity.

Main Methods:

• Blood samples from 49 healthy volunteers were collected in different tube types.
• Reference plasma glucose was immediately processed and stored at room temperature (RT) for up to 4 hours.
• Glucose levels were determined using a hexokinase method.

Main Results:

• Serum with clot activator, lithium heparin, and sodium fluoride/EDTA tubes showed unacceptable glucose bias after 4 hours at RT.
• GlucoEXACT tubes (sodium fluoride/citrate buffer) demonstrated a bias within the desirable limit (±1.8%) at 1, 2, and 4 hours.
• These results indicate superior glucose stability in GlucoEXACT tubes.

Conclusions:

• GlucoEXACT tubes containing sodium fluoride/citrate buffer effectively prevent glycolysis.
• These tubes are equivalent to reference plasma tubes for glucose analysis.
• They allow for up to a 4-hour delay in plasma separation without compromising glucose accuracy.