Evaluation of the BD Vacutainer(®) RST blood collection tube for routine chemistry analytes: clinical significance of differences and stability study

INTRODUCTION: Preanalytical variables account for most of laboratory errors. There is a wide range of factors that affect the reliability of laboratory report. Most convenient sample type for routine laboratory analysis is serum. BD Vacutainer(®) Rapid Serum Tube (RST) (Becton, Dickinson and Company, Franklin Lakes, NJ, USA) blood collection tube provides rapid clotting time allowing fast serum separation. Our aim was to evaluate the comparability of routine chemistry parameters in BD Vacutainer(®) RST blood collection tube in reference with the BD Vacutainer(®) Serum Separating Tubes II Advance Tube (SST) (Becton, Dickinson and Company, Franklin Lakes, NJ, USA). MATERIALS AND METHODS: Blood specimens were collected from 90 participants for evaluation on its results, clotting time and stability study of six routine biochemistry parameters: glucose (Glu), aspartate aminotransferase (AST), alanine aminotransferase (ALT), calcium (Ca), lactate dehidrogenase (LD) and potassium (K) measured with Olympus AU2700 analyzer (Beckman Coulter, Tokyo, Japan). The significance of the differences between samples was assessed by paired t-test or Wilcoxon Matched-Pairs Rank test after checking for normality. RESULTS: Clotting process was significantly shorter in the RSTs compared to SSTs (2.49 min vs. 19.47 min, respectively; P < 0.001). There was a statistically significant difference between the RST and SST II tubes for glucose, calcium and LD (P < 0.001). Differences for glucose and LD were also clinically significant. Analyte stability studies showed that all analytes were stable for 24 h at 4 °C. CONCLUSIONS: Most results (except LD and glucose) from RST are comparable with those from SST. In addition, RST tube provides shorter clotting time.