We used to see this and switched to lithium heparin tubes in the hope of reducing the micro-clots which were thought to be producing false positives. However, we still leave samples to stand for at least ten minutes on receipt as we find the tubes are not always mixed immediately post venepuncture so we can get clots even with lithium heparin tubes helen Helen Verrill Consultant Clinical Scientist | North Tees and Hartlepool NHS Foundation Trust T: 01642 624455| E: [log in to unmask] www.nth.nhs.uk <http://www.nth.nhs.uk/> <http://www.nth.nhs.uk/> <https://www.facebook.com/North-Tees-and-Hartlepool-NHS-Foundation-Trust -143318082359133/timeline/> <https://twitter.com/NTeesHpoolNHSFT> <https://www.youtube.com/user/NTeesHpoolNHSFT> <https://www.linkedin.com/company/north-tees-and-hartlepool-nhs-foundati on-trust/> From: Clinical biochemistry discussion list [mailto:[log in to unmask]] On Behalf Of Graham, Alastair Sent: 23 March 2016 16:53 To: [log in to unmask] Subject: Pre-analytical falsely elevated Troponin I results using Sarstedt Serum Gel Tube Dear Mailbase, We've have had a couple of false positive results on the Beckman DxI this week, which we think are due to the samples (Sarstedt serum gel) being centrifuged too soon post collection. We had 2 samples centrifuged within 6 minutes of collection which gave these false positives. They were identified as false positive as they were baseline/admission samples but the 12hr post chest pain samples were negative. I was wondering how other labs avoid this problem. Sarstedt say that their serum gel tube must be stored in an upright position for 30 mins to clot prior to centrifugation and then centrifuged for 10 mins. But how can labs report results within 1hr turnaround if these timings are used? Also to prevent false positive results do any labs take an aliquot of serum to be re-centrifuged before Troponin analysis? Many thanks Alastair Mr Alastair Graham FIBMS Section Manager Blood Sciences Borders General Hospital Melrose TD6 9BS Tel: 01896 826245 Email: [log in to unmask] <blocked::mailto:[log in to unmask]> ************************************************************************ ********** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the NHS Borders Servicedesk on 01896 82 77 77. Opinions expressed herein are those of the sender and do NOT represent the corporate position of NHS Borders This footnote also confirms that this email message has been swept by MIMEsweeper. *** NHS Borders ******************************************************************* ------ACB discussion List Information-------- This is an open discussion list for the academic and clinical community working in clinical biochemistry. Please note, archived messages are public and can be viewed via the internet. Views expressed are those of the individual and they are responsible for all message content. ACB Web Site http://www.acb.org.uk Green Laboratories Work http://www.laboratorymedicine.nhs.uk List Archives http://www.jiscmail.ac.uk/lists/ACB-CLIN-CHEM-GEN.html List Instructions (How to leave etc.) http://www.jiscmail.ac.uk/ This email and its attachments are intended for the above named only and may be confidential. If they have come to you in error you must take no action based on them, nor must you copy or show them to anyone; please reply to this email and highlight the error. The content of this email and its attachment(s) may be personal or contain personal opinions and unless expressly set out in this email, this email is not intended to form the basis of a binding agreement between North Tees and Hartlepool NHS Foundation Trust and you, or to be an expression of the Trust's position. Although we have taken steps to ensure that this email and attachments are free from any virus, we advise that in keeping with good computing practice the recipient should ensure they are actually virus free. ------ACB discussion List Information-------- This is an open discussion list for the academic and clinical community working in clinical biochemistry. Please note, archived messages are public and can be viewed via the internet. Views expressed are those of the individual and they are responsible for all message content. ACB Web Site http://www.acb.org.uk Green Laboratories Work http://www.laboratorymedicine.nhs.uk List Archives http://www.jiscmail.ac.uk/lists/ACB-CLIN-CHEM-GEN.html List Instructions (How to leave etc.) http://www.jiscmail.ac.uk/