Publications

Purpose: Blood collection devices are a potential source of pre-Analytical error in laboratory testing as the components from blood collection tubes and special tube additives may affect analyte concentrations and stability. A literature search on BD Vacutainer®SST™Serum Separation Tubes (SST) showed controversial data regarding effect of specimen collection tube on B12 levels and lacunae regarding the effect of pneumatic tube transport on B12 levels. Hence this study was undertaken to compare B12 values between BD Vacutainer®Serum and SST transported through pneumatic tube system. Methods: Blood was collected into both BD Vacutainer®Serum and SST. 30 pairs were transported through the pneumatic tube system and 20 manually. After centrifugation, the serum from BD Vacutainer®Serum was separated into Secondary Sample Cups and analyzed, while the SST were analyzed directly. Results: There was statistically significant difference between B12 values in BD Vacutainer®Serum and SST, the SST yields higher values (mean difference of 31.729 pg/mL, SE: 6.404, 95% CI of 18.845 to 44.613 and P-value of 0.01). Conclusion: Our study showed that the higher B12 value in SST could not be attributed to pneumatic tube transport as similar difference was obtained in B12 levels with manual transport. Thus it seems that the difference may be attributed to interference in the B12 assay due to gel. The clinical significance of this finding however, needs to be evaluated.