The new Greiner FC-Mix tubes equal the old Terumo ones and are useful as glucose stabilizer after prolonged storage of samples

Abstract

IntroductionThe aim of our study is to compare new Greiner tubes containing granulated citrate buffer with the Terumo ones and to verify if they are suitable for glucose stabilization after prolonged storage.Materials and methodsIn Study 1, blood was collected in two Terumo and two Greiner tubes from 40 healthy volunteers. Samples were stored at room temperature (RT) for 1 and 2 hours, respectively. Comparison was made by Deming regression. In Study 2, glucose was measured in a reference tube (N = 50), according to the ADA-NACB guidelines and in aliquots of Greiner samples maintained un-centrifuged at RT for 1, 2, 4 (N = 50) and 24, 48, 72 hours (N = 35).ResultsThere were insignificant mixed biases between the Terumo and Greiner tubes. Compared to reference (5.3 mmol/L), glucose concentration in the new tubes was 5.4 (P < 0.05), 5.4 (P < 0.05), 5.3 (P = 0.265), 5.2 (P = 0.156), 5.3 (P < 0.05) and 5.2 (P < 0.05) mmol/L after 1, 2, 4, 24, 48 and 72 hours at RT, respectively. There was no biological difference between any of the time points up to 48 h (bias < ± 1.95%).ConclusionsThe study shows that the new tubes perform equally well as the Terumo ones and ensure glucose stabilization up to 48 h as well as permit to create a link between the previous studies demonstrating the clinical utility of granulated citrate buffer and the future ones.

Glucose meters: What’s the laboratory reference glucose?

“…In our study, capillary glucose concentrations obtained from glucose meters and venous plasma reference glucose determined by laboratory instruments using NaF and citrate tubes were evaluated as in typical scenarios experienced in patient care. The novelty of our study is that is the first to compare capillary whole blood glucose to reference plasma glucose using the two universally available tubes containing citrate in a liquid and granular form together with the old NaF-containing tubes (10,16). Significant biases in glucose concentrations were observed between glucose meters and reference plasma glucose when different plasma tubes were used.…”

“…Since the instability of glucose in blood can introduce important bias in the assessment of glucose meters, we have planned a preliminary study to quantify the bias of glucose measured by two different glucose meters (i.e., Abbott FreeStyle Precision Neo and Roche Cobas Accu-Chek Inform II) based on ADA and ISO 15197:2013 requirements with respect to reference glucose measured in laboratories using NaF and the two universally commercially available recommended citrate-containing tubes (GlucoEXACT from Sarstedt and FC-Mix from Greiner Bio-One) (10,12,16). mixture tubes were used, respectively.…”