gray 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 ?
Q I ran a glucose on one patient on both a gray top tube plasma and SST tube serum drawn at the same time and I got the following results:
Gray top tube plasma glucose: 91mmol/dl (reference range 65-1000.