The certification of the copy number concentration of solutions of plasmid DNA containing a BCR-ABL b3a2 transcript fragment : certified reference materials: ERM-AD623a, ERM-AD623b, ERM-AD623c, ERM-AD623d, ERM-AD623e, ERM-AD623f

This report describes the production of a set of plasmid solutions, ERM®-AD623a, b, c, d, e, and f, certified for the copy number ratio of specific desoxyribonucleic acid (DNA) fragments per plasmid and for the copy number concentration of the plasmid. The material has been produced following ISO Guide 34:2009 [1]. DNA fragments specific for the transcript of breakpoint cluster region gene (BCR), the transcript of the glucuronidase beta gene (GUSB) and the fusion transcript from the BCR gene and the c-abl oncogene 1 (BCR-ABL b3a2) were cloned into a pUC18 vector to construct the pIRMM-0099 plasmid. The sequence identity of the pIRMM-0099 plasmid was determined by dye terminator cycle sequencing of the entire plasmid. The plasmid was diluted to six different concentration levels. Between unit-heterogeneity has been quantified and stability during dispatch and storage have been assessed in accordance with ISO Guide 35:2006 [2]. The material was characterised by an intercomparison among laboratories of demonstrated competence and adhering to ISO/IEC 17025:2005 [3]. Uncertainties of the certified values were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) [4] and include uncertainties related to possible heterogeneity and instability and to characterisation. The CRM has been accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Material consortium.