gray top tube

(redirected from Grey Top Tube)
A blood collection tube containing powdered sodium fluoride and/or potassium oxalate, which inhibits glycolysis; ‘gray tops’ are used for glucose tolerance testing because glycolysis in the red cells would cause false-low glucose, for measuring lactate—transported on ice—lactate tolerance

gray top tube

Lab medicine A blood collection tube containing powdered sodium fluoride and/or potassium oxalate, which inhibits glycolysis; 'gray tops' are used for GTT–as glycolysis in the RBCs would cause false-low glucose, for measuring lactate–transported on ice, lactate tolerance. See Glucose tolerance test.
References in periodicals archive ?
The grey top tube contains potassium oxalate as an anticoagulant and sodium fluoride as a preservative that is used to preserve glucose in whole blood.
Grey top tubes should be at least 65 percent to 80 percent full, gently mixed by inverting five or six times, and placed immediately at 4[degrees]C for up to 30 minutes before spinning in a centrifuge.
In conclusion, grey top tubes processed appropriately are the tube of choice for blood glucose analysis, but SST tubes can also be used with reproducible results.