User manual

Droplet Digital
™
PCR Applications Guide | 97
Fig. 4. Relative contribution of partitioning and subsampling errors to ddPCR error. CPD, copies per
droplet; CV, coefficient of variation.
CV, %
5
4
3
2
1
0
0 1 2 3 4 5 6
CPD
0.11 5.7
Partitioning error
Subsampling error
ddPCR error (15,000 droplets)
Subsampling error
Figure 4 illustrates the technical error as a function of CPD for 10,000 droplets. Note that
the coefficient of variation (CV) is extremely low across the entire range covered here.
The dotted lines show the region with CV <2.5%: 0.17–5.1 CPD.
The black and blue curves match very closely at low CPD, meaning that subsampling error
is more significant than the partitioning error in this example. The blue curve goes up with
high CPD as the contribution of partitioning error increases.
Note: The actual CV calculations contain a Bayesian adjustment at very low and very high
CPD (<100 occupied or <100 empty droplets).
Appendix B: Technical Error Bars in Droplet Digital
™
PCR