Amplification with ddPCRwas performed with either a CFX96 or
T100 PCR thermocycler with gradient function (Bio-Rad, Munich,
Germany). The master-mix employed was the “ddPCR Supermix for
Probes” (Cat. No. 186-3010, Bio-Rad), with a total reaction volume
of 22 ml, comprising 1x master-mix, primers and probes at appropriate
concentrations, and 5 ml sample DNA.