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Hi It is alarming that Randox cannot tell you how it standardises its assay! It must at the very least have its own working standard using (maybe) a weighed-in standard solution with a known uncertainty, or it could not produce an assay! Randox's web page <http://www.randoxonlinestore.com/Assessment-of-Diabetic-Ketoacidosis> for this assay says (in blue) (my bullets and comments in italics) The Randox assay offers the following key benefits: - Wide measuring range 0.1 – 5.75 mmol/l *(using SI units means there exists a full traceability chain back to an SI definition of the measurand, which implies that higher order reference methods and materials exist!)* - Suitable for use with both serum and plasma samples - Limited interference from haemoglobin - Excellent precision - Excellent correlation to standard methods *(which methods, and what standards to they use? Where is the evidence?)* Randox must be able to support these claims so that users can verify them so as to meet ISO 15189 requirements for verification! A practical suggestion: You can buy the sodium salt <http://www.sigmaaldrich.com/catalog/product/aldrich/54965?lang=en®ion=GB> with 99% purity from Sigma Aldrich, so I guess you could do a recovery study to assess trueness using that, but would that satisfy UKASs requirements? (Their policy on Traceability was updated last year (TPS 41) and a pdf is available from a table of documents here <http://www.ukas.com/technical-information/publications-and-tech-articles/publications/Technical_Policy_Statements.asp> .) I doubt if this is an isolated example, as other manufacturers may be just as reluctant to divulge what they might regard as commercially sensitive information. Does BIVDA have a view on how to tackle this problem? This is a good example of how adhering to the requirements of ISO 15189 may open up to detailed scrutiny contentious areas of standardisation and calibration and ultimately help improve accuracy and comparability of test results. Cheers Jonathan Middle On Wed, Jul 15, 2015 at 10:40 AM, Stephen Davis (Cwm Taf UHB - Biochemistry) <[log in to unmask]> wrote: > Our recent UKAS inspection highlighted lack of traceability for > calibration of our 3-hydroxybutyrate assay. > > The laboratory is still unable to provide sufficient robust evidence from > the manufacturer that the hydroxybutyrate assay uses a calibrator that has > any form of international endorsement or consensus of its traceability. > > > > We have repeatedly contacted the manufacturer (Randox) requesting > information about the traceability of calibration for their > 3-hydroxybutyrate assay but they have been unable to provide any evidence > nor do they appear to understand the problem we face. > > > > I wondered if any other lab has come across the same (or similar) problem > and if they have found a way to meet the inspector’s concerns. We are > reluctant to simply remove hydroxybutyrate from the scope of the > inspection. Is there another hydroxybutyrate assay we could run (on Roche > c501) that has traceability? > > > > Many thanks for any help offered. > > > > Regards > > > > Steve > > > > ---------------------------------------------------------- > > *Stephen Davis* BSc (Hons), MSc, CSci > > *Principal Biochemist* > > *Biochemistry* > > > > *Cwm Taf University Health Board | *Royal Glamorgan Hospital | Ynysmaerdy > | Llantrisant | Rhondda Cynon Taf | CF72 8XR > > *Bwrdd Iechyd Prifysgol Cwm Taf | *Ysbyty Brenhinol Morgannwg | > Ynysmaerdy | Llantrisant | Rhondda Cynon Taf | CF72 8XR > > > > phone | ffôn : 01443 443357 or 01443 443443 ext 3357 > > *[log in to unmask] <[log in to unmask]>* > > > > Please consider the environment before printing this email > > A wnewch chi ystyried yr amgylchedd cyn argraffu’r neges hon. > > > > > > ------------------------------ > > *Please consider the environment before printing this email* > > > > *A wnewch chi ystyried yr amgylchedd cyn argraffu’r neges hon* > > Link to Cwm Taf Health Board email disclaimer - Disclaimer > <http://www.wales.nhs.uk/sitesplus/865/page/40884> > > Dolen gyswllt at ymwadiad Bwrdd Iechyd Prifysgol Cwm Taf - Ymwadiad > <http://www.bipcwmtaf.wales.nhs.uk/preifatrwydd-polisi> > > Follow us on Twitter @CwmTaf <https://twitter.com/cwmtaf> > > Dilynwch ni ar Twitter @CwmTaf <https://twitter.com/cwmtaf> > > **Cwm Taf Health Board is the operational name of Cwm Taf University Local > Health Board* > > **Bwrdd Iechyd Prifysgol Cwm Taf yw enw gweithredol Bwrdd Iechyd Lleol > Prifysgol Cwm Taf* > > ------------------------------ > > ------ACB discussion List Information-------- This is an open discussion > list for the academic and clinical community working in clinical > biochemistry. 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