Clin Chem Lab Med 2015; 53(2): 231–238 Cevdet Zungun, Fatma MeriÇ Yılmaz*, Elif Guney Boru and Canan Topcuoglu Comparison of Improvacuter™ tubes with BD Vacutainer™ tubes for various hormones in the aspects of stability and influence of gel separators DOI 10.1515/cclm-2014-0583 Received June 2, 2014; accepted July 21, 2014; previously published online August 15, 2014 Abstract Background: Validation of blood collection tubes are important to determine the role of different collection tubes which influence the assurance of laboratory results. We compared two different tubes (Improvacuter ™ and Becton Dickinson [BD] Vacutainer ™ ) and investigated the effect of gel and storage time in comparison with each other. Methods: We compared the results of nine immunoas- says performed on UniCel ® DxI 800 using blood samples collected in BD Vacutainer SST II Advance tubes, Impro- vacuter Gel and Clot Activator tubes, BD Vacutainer Clot Activator tubes and Improvacuter tubes. Analytes were measured in all tubes on 3 consecutive days to study the effect of long-term storage. Evaluation of clinical signifi- cance was performed based on total allowable error. Results: Estradiol and testosterone concentrations obtained from Improvacuter Gel and Clot Activator tubes and BD Vacutainer SST II Advance tubes remained below the lower limits of analytical range for the same analytes while they were within the limits in BD Vacutainer Clot Activator tubes and Improvacuter tubes. Statistical sig- nificance of stability was not clinically significant for the hormone parameters we tested in all four tubes. Conclusions: Gel containing tubes (both BD and Improve) gave comparable results with the tubes which do not con- tain gel except for estradiol and testosterone. The use of gel containing tubes for estradiol and testosterone are not recommended on UniCel ® DxI 800 according to our results. The change in the analyte concentrations over 48 h remained within the TE A limits for the studied ana- lytes. Improve tubes gave similar results to BD tubes. Keywords: BD Vacutainer; gel separator tube; hormone assay; improvacuter; stability. Introduction In order to minimize preanalytical errors due to prolonged contact of serum with blood cells, Clinical and Laboratory Standards Institute (CLSI) recommends performing the analysis within 2 h following blood collection [1]. The use of serum separator gels has found acceptance among clin- ical laboratories since they were manufactured and intro- duced approximately 40 years ago by Becton, Dickinson and Company (BD, Franklin Lakes, NJ, USA). The separa- tor gel formation which is made from polymeric material provides some benefits due to its specific density [2]. The layer between blood cells and serum after centrifugation means the primary tube can be used directly on an ana- lyzer and diminishes the need of transfering samples into a secondary tube. In addition, this closed system provided by the gel separator not only facilitates sampling, process- ing, transport and storage of specimens but also prevents hemolysis upon prolonged storage. After the introduction of gel separator tubes, many studies investigating the interaction between polymeric gel and analytes in serum have been performed. Although significant differences in many routine biochemical analysis have not been seen, many articles have been published reporting significant declines especially in therapeutic drug levels [3, 4]. Recently, published arti- cles have reported the significant effects of gel separator tubes on total triiodothyronine [5] and vitamin B12 [6] immunoassays. In general, when compared with routine biochemi- cal parameters, tumor markers and hormones are the *Corresponding author: Prof. Dr. Fatma MeriÇ Yılmaz, Ankara Numune Training and Research Hospital, Clinical Biochemistry Laboratory, Altındağ, Ankara, Turkey, Phone: +90 312 5085054, Fax: +90 312 3621364, E-mail: fatmamericyilmaz@hotmail.com; and Faculty of Medicine, Biochemistry Department, Yıldırım Beyazıt University, Ankara, Turkey Cevdet Zungun, Elif Guney Boru and Canan Topcuoglu: Clinical Biochemistry, Ankara Numune Training and Research Hospital, Ankara, Turkey Brought to you by | University of Louisville Authenticated Download Date | 2/4/15 10:33 AM