Each assembled ddPCR reaction mixture was loaded in duplicate into the sample wells of an eight-channel disposable droplet generator cartridge (BioRad) and droplet generation oil (BioRad) was added.
A Berglund-Liu droplet generator was used to generate a stream of droplets, approximately 63 microns in diameter and 6.5 droplet diameters apart.
Reactions were performed in quadruplicate and droplets were generated using a Droplet Generator according to the manufacturer's instructions.
This measured droplet volume and associated uncertainty agrees with the manufacturer's independently estimated value of 0.89 nL for droplets generated from the eight channel droplet generator cartridges (Bio-Rad, personal communication).
Droplets were generated in a QX100 droplet generator (BioRad, Hercules, California, USA).
Droplets were generated by a QX200™ droplet generator (Bio-Rad, Hercules, California, USA).
Emulsified 1 nL reaction droplets were generated using a QX100 Droplet generator (Bio-Rad) and a droplet generator DG8 cartridge (Bio-Rad) containing 20 μl of reaction mixture and 70 μl of ddPCR droplet generation oil (Bio-Rad) per well.
Droplets were generated by the QX100 droplet generator, and 40 μL of droplets was transferred, using a multichannel pipette, into a 96-well plate.
The remainder could be mainly attributed to the variation in volume of droplets generated from different wells of the droplet generator cartridge.
After loading a 20‐μL PCR reaction and 70 μL of droplet generation oil to the exclusive chamber, the droplet generator produces approximately 20 000 droplets per sample.
After droplets were generated from plasma DNA (QX100 Droplet Generator, Biorad), and PCR performed on all droplets, a fluorescent droplet reader (QX100 Droplet Reader, Biorad) then read the FAM and VIC signal of the probes in each droplet.
