RT Journal Article SR Electronic T1 An International Inter-Laboratory Digital PCR Study Demonstrates High Reproducibility for the Measurement of a Rare Sequence Variant JF bioRxiv FD Cold Spring Harbor Laboratory SP 077917 DO 10.1101/077917 A1 Alexandra S. Whale A1 Alison S. Devonshire A1 George Karlin-Neumann A1 Jack Regan A1 Leanne Javier A1 Simon Cowen A1 Ana Fernandez-Gonzalez A1 Gerwyn M. Jones A1 Nicholas Redshaw A1 Julia Beck A1 Andreas W. Berger A1 Valérie Combaret A1 Nina Dahl Kjersgaard A1 Lisa Davis A1 Frederic Fina A1 Tim Forshew A1 Rikke Fredslund Andersen A1 Silvia Galbiati A1 Álvaro González Hernández A1 Charles A. Haynes A1 Filip Janku A1 Roger Lacave A1 Justin Lee A1 Vilas Mistry A1 Alexandra Pender A1 Anne Pradines A1 Charlotte Proudhon A1 Lao Saal A1 Elliot Stieglitz A1 Bryan Ulrich A1 Carole A. Foy A1 Helen Parkes A1 Svilen Tzonev A1 Jim F. Huggett YR 2016 UL http://biorxiv.org/content/early/2016/09/28/077917.abstract AB This study tested the claim that digital PCR (dPCR) can offer highly reproducible quantitative measurements in disparate labs. Twenty-one laboratories measured four blinded samples containing different quantities of a KRAS fragment encoding G12D, an important genetic marker for guiding therapy of certain cancers. This marker is challenging to quantify reproducibly using qPCR or NGS due to the presence of competing wild type sequences and the need for calibration. Using dPCR, eighteen laboratories were able to quantify the G12D marker within 12% of each other in all samples. Three laboratories appeared to measure consistently outlying results; however, proper application of a follow-up analysis recommendation rectified their data. Our findings show that dPCR has demonstrable reproducibility across a large number of laboratories without calibration and could enable the reproducible application of molecular stratification to guide therapy, and potentially for molecular diagnostics.SIGNIFICANCE STATEMENT The poor reproducibility of molecular diagnostic methods limits their application in part due to the challenges associated with calibration of what are relative measurement approaches. In this study we investigate the performance of one of the only absolute measurement methods available today, digital PCR (dPCR), and demonstrated that when compared across twenty-one laboratories, dPCR has unprecedented reproducibility. These results were achieved when measuring a challenging single nucleotide variant and without calibration to any reference samples. This opens the possibility for dPCR to offer a method to transform reproducibility in the molecular diagnostic field, both by direct use as well as in support of other currently used clinical methods.