Libraries were prepared with
Nextera Rapid Capture Custom Enrichment Kit (Illumina Inc., San Diego, CA, USA), according to the manufacturer’s protocol. Preparation of libraries was performed starting from up to 10–150 ng of plasma ctDNA and 50–100 ng of gDNA from PBMCs (as corresponding normal reference, or hg19 when germ-line DNA from the patient was not available). gDNA was fragmented using transposones, adding simultaneously adapter sequences. For ctDNA libraries preparation was used NEBNext
® Ultra™ DNA Library Prep Kit for Illumina
® (New England BioLabs Inc., Ipswich MA). Purified tagmented gDNA and ctDNA was used as template for subsequent PCR to introduce unique sample barcodes. Fragments’ size distribution of the DNA was assessed using the
2100 Bioanalyzer with a
High Sensitivity DNA assay kit (Agilent Technologies, Santa Clara, CA). Equal amount of DNA libraries were pooled and subjected to targeted panel hybridization capture. Libraries were then sequenced using Illumina MiSeq or
NextSeq500 sequencer (Illumina Inc., San Diego, CA, USA).
Siravegna G., Mussolin B., Buscarino M., Corti G., Cassingena A., Crisafulli G., Ponzetti A., Cremolini C., Amatu A., Lauricella C., Lamba S., Hobor S., Avallone A., Valtorta E., Rospo G., Medico E., Motta V., Antoniotti C., Tatangelo F., Bellosillo B., Veronese S., Budillon A., Montagut C., Racca P., Marsoni S., Falcone A., Corcoran R.B., Di Nicolantonio F., Loupakis F., Siena S., Sartore-Bianchi A, & Bardelli A. (2015). Monitoring clonal evolution and resistance to EGFR blockade in the blood of metastatic colorectal cancer patients. Nature medicine, 21(7), 795-801.