M. J. Duffy and J. Crown, Companion biomarkers: paving the pathway to personalized treatment for cancer, Clin Chem, vol.59, pp.1447-56, 2013.

F. Diehl, M. Li, D. Dressman, Y. He, D. Shen et al., Detection and quantification of mutations in the plasma of patients with colorectal tumors, Proc Natl Acad Sci U S A, vol.102, pp.16368-73, 2005.

M. Westwood, T. Van-asselt, B. Ramaekers, P. Whiting, M. Joore et al., KRAS mutation testing of tumours in adults with metastatic colorectal cancer: a systematic review and cost-effectiveness analysis, Health Technol Assess, vol.18, pp.1-132, 2014.

J. C. Wan, C. Massie, J. Garcia-corbacho, F. Mouliere, J. D. Brenton et al., Liquid biopsies come of age: towards implementation of circulating tumour DNA, Nat Rev Cancer, vol.17, pp.223-261, 2017.

L. Tembuyser, M. J. Ligtenberg, N. Normanno, S. Delen, J. H. Van-krieken et al., Higher quality of molecular testing, an unfulfilled priority: results from external quality assessment for KRAS mutation testing in colorectal cancer, J Mol Diagn, vol.16, pp.371-378, 2014.

H. W. Vesper and L. M. Thienpont, Traceability in laboratory medicine, Clin Chem, vol.55, pp.1067-75, 2009.

G. H. White, Metrological traceability in clinical biochemistry, Ann Clin Biochem, vol.48, pp.393-409, 2011.

J. Saldanha, M. Silvy, N. Beaufils, R. Arlinghaus, G. Barbany et al., Characterization of a reference material for BCR-ABL (M-BCR) mRNA quantitation by realtime amplification assays: towards new standards for gene expression measurements, Leukemia, vol.21, pp.1481-1488, 2007.

H. White, L. Deprez, P. Corbisier, V. Hall, F. Lin et al., A certified plasmid reference material for the standardisation of BCR-ABL1 mRNA quantification by realtime quantitative PCR, Leukemia, vol.29, pp.369-76, 2015.

C. J. Lih, H. Si, B. Das, R. D. Harrington, K. N. Harper et al., Certified DNA reference materials to compare HER2 gene amplification measurements using nextgeneration sequencing methods, J Mol Diagn, vol.18, pp.753-61, 2016.

, JCTLM database: laboratory medicine and in vitro diagnostics, 2017.

S. Bhat, J. Herrmann, P. Armishaw, P. Corbisier, and K. R. Emslie, Single molecule detection in nanofluidic digital array enables accurate measurement of DNA copy number, Anal Bioanal Chem, vol.394, pp.457-67, 2009.

R. Sanders, J. F. Huggett, C. A. Bushell, S. Cowen, D. J. Scott et al., Evaluation of digital PCR for absolute DNA quantification, Anal Chem, vol.83, pp.6474-84, 2011.

B. Vogelstein, K. W. Kinzler, and P. Digital, Proc Natl Acad Sci U S A, vol.96, pp.9236-9277, 1999.

H. B. Yoo, S. R. Park, L. Dong, J. Wang, Z. Sui et al., International comparison of enumeration-based quantification of DNA copy-concentration using flow cytometric counting and digital polymerase chain reaction, Anal Chem, vol.88, pp.12169-76, 2016.

A. S. Whale, A. S. Devonshire, G. Karlin-neumann, J. Regan, J. L. Cowen et al., International interlaboratory digital PCR study demonstrating high reproducibility for the measurement of a rare sequence variant, Anal Chem, vol.89, pp.1724-1757, 2017.

B. Si-brochure, , 2017.

J. F. Huggett, C. A. Foy, V. Benes, K. Emslie, J. A. Garson et al., The digital MIQE guidelines: minimum information for publication of quantitative digital PCR experiments, Clin Chem, vol.59, pp.892-902, 2013.

V. Taly, D. Pekin, L. Benhaim, S. K. Kotsopoulos, L. Corre et al., Multiplex picodroplet digital PCR to detect KRAS mutations in circulating DNA from the plasma of colorectal cancer patients, Clin Chem, vol.59, pp.1722-1753, 2013.
URL : https://hal.archives-ouvertes.fr/inserm-02299581

P. Corbisier, L. Pinheiro, S. Mazoua, A. M. Kortekaas, P. Y. Chung et al., DNA copy number concentration measured by digital and droplet digital quantitative PCR using certified reference materials, Anal Bioanal Chem, vol.407, pp.1831-1871, 2015.

A. S. Whale, S. Cowen, C. A. Foy, and J. F. Huggett, Methods for applying accurate digital PCR analysis on low copy DNA samples, PLoS One, vol.8, p.58177, 2013.

A. S. Devonshire, A. S. Whale, A. Gutteridge, G. Jones, S. Cowen et al., Towards standardisation of cell-free DNA measurement in plasma: controls for extraction efficiency, fragment size bias and quantification, Anal Bioanal Chem, vol.406, pp.6499-512, 2014.

S. Weaver, S. Dube, A. Mir, J. Qin, G. Sun et al., Taking qPCR to a higher level: analysis of CNV reveals the power of high throughput qPCR to enhance quantitative resolution, Methods, vol.50, pp.271-277, 2010.

J. F. Huggett, S. Cowen, and C. A. Foy, Considerations for digital PCR as an accurate molecular diagnostic tool, Clin Chem, vol.61, pp.79-88, 2015.

B. K. Jacobs, E. Goetghebeur, and L. Clement, Impact of variance components on reliability of absolute quantification using digital PCR, BMC Bioinformatics, vol.15, p.283, 2014.

E. Heitzer, P. Ulz, and J. B. Geigl, Circulating tumor DNA as a liquid biopsy for cancer, Clin Chem, vol.61, pp.112-135, 2015.

A. S. Devonshire, I. Honeyborne, A. Gutteridge, A. S. Whale, G. Nixon et al., Highly reproducible absolute quantification of Mycobacterium tuberculosis complex by digital PCR, Anal Chem, vol.87, pp.3706-3719, 2015.

C. A. Milbury, Q. Zhong, J. Lin, M. Williams, J. Olson et al., Determining lower limits of detection of digital PCR assays for cancer-related gene mutations, Biomol Detect Quantif, vol.1, pp.8-22, 2014.

A. S. Whale, C. Bushell, P. R. Grant, S. Cowen, I. Guttierrezaguirre et al., Detection of rare drug resistance mutations by digital PCR in a human influenza A virus model system and clinical samples, J Clin Microbiol, vol.54, pp.392-400, 2016.

, In vitro diagnostic medical devices-measurement of quantities in samples of biological origin-requirements for content and presentation of reference measurement procedures. ISO Guide 15193

A. S. Whale, J. F. Huggett, and S. Tzonev, Fundamentals of multiplexing with digital PCR, Biomol Detect Quantif, vol.10, pp.15-23, 2016.

E. Cobas and . Sqi-brochure, introducing the semiquantitative index (SQI) reporting tool, 2018.

, International Organization of Standardization. Medical laboratories-requirements for quality and competence. ISO Guide 15189, p.2012

, Medical devices-quality management systems-requirements for regulatory purposes. ISO Guide 13485, p.2016

J. F. Fryer, A. B. Heath, and P. D. Minor, A collaborative study to establish the 1st WHO International Standard for human cytomegalovirus for nucleic acid amplification technology, Biologicals, vol.44, pp.242-51, 2016.

S. Scott, D. Travis, L. Whitby, J. Bainbridge, N. Cross et al., Measurement of BCR-ABL1 by RT-qPCR in chronic myeloid leukaemia: findings from an International EQA Programme, Br J Haematol, vol.177, pp.414-436, 2017.

, Collaborative study to evaluate the proposed WHO 1st International Reference Panel for genomic KRAS codons 12 and 13 mutations, WHO. Expert Committee on Biological Standardization, vol.17, p.2017, 2017.

R. T. Hayden, Z. Gu, S. S. Sam, Y. Sun, L. Tang et al., Comparative evaluation of three commercial quantitative cytomegalovirus standards by use of digital and real-time PCR, J Clin Microbiol, vol.53, pp.1500-1505, 2015.

L. Dong, Y. Meng, Z. Sui, J. Wang, L. Wu et al., Comparison of four digital PCR platforms for accurate quantification of DNA copy number of a certified plasmid DNA reference material, Sci Rep, vol.5, p.13174, 2015.

A. B. Kosir, C. Divieto, J. Pavsic, S. Pavarelli, D. Dobnik et al., Droplet volume variability as a critical factor for accuracy of absolute quantification using droplet digital PCR, Anal Bioanal Chem, vol.409, pp.6689-97, 2017.

L. B. Pinheiro, V. A. Coleman, C. M. Hindson, J. Herrmann, B. J. Hindson et al., Evaluation of a droplet digital polymerase chain reaction format for DNA copy number quantification, Anal Chem, vol.84, pp.1003-1014, 2012.

J. A. Dagata, N. Farkas, and J. A. Kramar, Method for measuring the volume of nominally 100 ?m diameter spherical water-in-oil emulsion droplets. NIST Special Publication 260 -184, 2016.

M. J. Holden, S. A. Rabb, Y. B. Tewari, and M. R. Winchester, Traceable phosphorus measurements by ICP-OES and HPLC for the quantitation of DNA, Anal Chem, vol.79, pp.1536-1577, 2007.

L. Dong, Y. Meng, J. Wang, and Y. Liu, Evaluation of droplet digital PCR for characterizing plasmid reference material used for quantifying ammonia oxidizers and denitrifiers, Anal Bioanal Chem, vol.406, pp.1701-1713, 2014.

M. C. Kline, E. L. Romsos, and D. L. Duewer, Evaluating digital PCR for the quantification of human genomic DNA: accessible amplifiable targets, Anal Chem, vol.88, pp.2132-2141, 2016.

D. Gale, A. Lawson, K. Howarth, M. Madi, B. Durham et al., Development of a highly sensitive liquid biopsy platform to detect clinically-relevant cancer mutations at low allele fractions in cell-free DNA, PLoS One, vol.13, p.194630, 2018.

R. J. Haynes, M. C. Kline, B. Toman, C. Scott, P. Wallace et al., Standard reference material 2366 for measurement of human cytomegalovirus DNA, J Mol Diagn, vol.15, pp.177-85, 2013.

R. Sanders, D. J. Mason, C. A. Foy, and J. F. Huggett, Evaluation of digital PCR for absolute RNA quantification, PLoS One, vol.8, p.75296, 2013.

, /746 of the European Parliament and of the Council of 5 April 2017 on in vitro diagnostic medical devices. Annex I chapter II: requirements regarding performance, design and manufacture, Brussels, 2017.

G. M. Jones, E. Busby, J. A. Garson, P. R. Grant, E. Nastouli et al., Digital PCR dynamic range is approaching that of real-time quantitative PCR, Biomol Detect Quantif, vol.10, pp.31-34, 2016.

, International Organization of Standardization. General requirements for the competence of calibration and testing laboratories. ISO/IEC 17025, 2005.

, Uncertainty of measurement-part 3: guide to the expression of uncertainty in measurement (GUM: 1995). ISO/IEC Guide 98 -3, 2008.

, Eurachem/CITAC guide: quantifying uncertainty in analytical measurement, 2012.