An antiglycolytic agent has to be added to inhibit the glycolytic enzymes.
Permitting the blood to clot and separate the sera of the blood samples therefore has advantage over using the whole blood with addition of anticoagulants, antiglycolytic agents, chilling or acidification as there is only insignificant fall in glucose concentration from the level obtained immediately on collection of blood specimen.
In case a delay in blood separation is expected, the use of acid citrate is suggested as an immediate antiglycolytic agent
. However, these tubes have been recently described, are not broadly available, and their use might require revisiting of the glucose cut-off thresholds for the diagnosis of diabetes mellitus, recommended by the ADA, World Health Organization, and other professional bodies, which may not easily and practically be considered for implementation.
(1) Sodium fluoride commonly has been used to stabilize the glucose, but it is not effective as an antiglycolytic agent
for an hour or more after blood collection, with a mean glucose loss of about 5% in the first four hours.
From a practical standpoint, the best way to achieve this goal is discovery of an antiglycolytic agent that could be added to collection tubes but did not alter cellular integrity or interfere in common analytical methodologies.
Aliquots of heparinized whole blood (0.96 mL) were pipetted into microcentrifuge tubes containing 0.040 mL of saline or antiglycolytic agent in saline.
Interference of D-mannose, antiglycolytic agent, in glucose determinations [Letter].
Stability of plasma lactate in vitro in the presence of antiglycolytic agents
. Clin Chem 1994;40:1327-30.
If analysis will be delayed for longer than one hour following collection, specimens for glucose analysis should be collected into tubes containing antiglycolytic agents
, such as sodium fluoride.
One set of three tubes of blood was collected in the morning by one trained phlebotomist from each of eight volunteers after an overnight fast: a 10-mL tube containing 18 mg of EDTA, a 4.0-mL tube containing 8 mg of potassium oxalate and 10 mg of sodium fluoride (as antiglycolytic agents
), and a 9.5-mL serum separator (SST) tube (Becton Dickinson).
The use of antiglycolytic agents
is commonplace for glucose measurements.