1. Evaluation of Beckton-Dickinson PST II and SST II Blood Collection Tubes P Graham, B Martin, M Roser, G Jones Department of Chemical Pathology, St Vincent’s Hospital, Sydney

2. Background Becton-Dickinson have introduced new tubes for plasma and serum. Acrylic gel separator. Terminology –PST II - Plasma separator –SST II - Serum separator No independent studies identified. Limited BD data available.

4. Our Questions? 1) Are the new BD gel tubes OK for routine use? 2) How long are samples stable when stored on the gel? 3) Is it OK to re-centrifuge samples stored on the gel?

5. 3 Experiments 1) Tube comparison - to “gold standard” 2) Stability Study - Healthy volunteers (all analytes) - Patient samples (unstable analytes) 3) Re-Centrifugation study - Patient samples +/- re-spin

6. Methods - Tube Comparison Blood collected from 5 volunteers Non-gel clot activator, PST, PST II, SST, SST II Centrifuged within 1 hour of collection Analysed within 2-3 hours. Results compared to the non-gel tube. Differences evaluated using Student’s T test for statistical significance Comparison to the RCPA AACB Allowable Limits of Performance (ALP) for clinical significance. –>0.25 x ALP used as screen for significance

7. Methods - Analysis

8. Results - Tube Comparison Relative differences compared to plain serum tube:

9. Tube Comparison Conclusion PST II and SST II tubes acceptable for all analytes tested. Further testing showed folate acceptable for serum and plasma on Access (Not on Centaur).

10. Methods - Storage Stability Tubes from comparison study PST II and SST II Gel tubes stored at (2-6 °C). Re-centrifuged and re-analysed at 1,3 and 7 days.

11. Stability Study - Raw data Changes as multiples of ALP PST IISST II

12. Category 1 - Stable Analytes All Averages (nearly) within +/- 0.5 ALP PST IISST II

13. Category 1 - Stable Analytes Roche Hitachi 917 –Albumin, ALT, ALP, amylase, AST, cholesterol, CK, creatinine, GGT, HDL cholesterol, iron, magnesium, total protein, transferrin, triglycerides, uric acid, urea Beckman Coulter Access –Vitamin B12, folate, insulin Abbott AxSYM –LH, FSH, TSH, FT4, FT3, CK-MB, PRL

14. Category 2: Analytes with poor precision HCO3 in PSTII Sodium in PSTII Sodium, Chloride, Bicarbonate, Calcium No obvious pattern

15. Category 2 Variation in results was similar to between-day precision. Accepted as stable to 7 days. Category 2: Analytes with poor precision

16. Category 3 - Clearly unstable For Further Analysis PST IISST II

17. Methods Re-Spin Study

18. Effect of Re-Centrifugation Change in Potassium (mmol/L)

19. Analytes limited to <7 days

20. Conclusion The PST II and SST II gel tubes from BD are suitable for routine use. Most analytes are suitable for analysis up to 7 days storage at 2-8°C. Limits have been placed on analysis of stored samples for some analytes. Samples for Glucose, LD and K + should not be re-spun in primary tube. We acknowledge the support of Becton Dickinson for supply of tubes for testing. These powerpoint slides will be available at www.sydpath.stvincents.com.au after the conference.