Background: Delayed sample processing can affect accurate glucose measurement. Our aim was to investigate the stability of glucose in samples collected in serum, sodium fluoride/potassium oxalate (NaF/KOx) and Glucomedics tubes processed according to different controlled pre-centrifugation delays (up to 180 min after venipuncture) in order to simulate prolonged sample transport between venipuncture and centrifugation.Methods: Samples were collected from healthy volunteers (n=80) into either serum or NaF/KOx and Glucomedics tubes. Glucose concentration was measured in samples centrifuged immediately after venipuncture and compared with tubes processed with a delay of 60, 120 and 180 min prior to centrifugation. Differences between baseline and respective delayed centrifugation glucose value for each tube type were tested using the paired t-test. Mean bias calculated for each tube type and delay protocol was compared to recommended quality specifications for glucose (2.2%).Results: Glucose concentrations measured in all three delayed tube types were lower in comparison to respective baseline glucose concentrations measured in immediately processed tube (pConclusions: Glucose stability in un-centrifuged Glucomedics tubes is much superior to serum and NaF/KOx tubes. Glucomedics tubes can be left un-centrifuged for up to 3 h without affecting glucose concentration.