Table 2.

Characteristics of SNP ddPCR assays defined by measuring copies of alleles in mixtures of gDNA/gBlocks with a background of 50,000 copies of major alleles per ddPCR reaction.

Assay target	Target allele	FPS [%]	LOD [%]	LOQ [%]
rs1707473	G	0.00	<0.09	<0.09
	T	0.02	<0.13	0.13–0.23
rs2691527	C	0.03	0.05–0.08	0.03–0.08
	T	0.04	0.05–0.08	0.27–0.42
rs7687645	C	0.14	0.08–0.1	0.21–0.47
	T	0.03	0.08–0.1	0.16–0.38
rs1420530	C	0.03	0.05–0.08	0.08–0.26
	T	0.03	0.05–0.08	0.05–0.09
rs9289628	C	0.09	0–0.05	0.13–0.22
	T	0.07	0.05–0.08	0.13–0.24
rs6070149	C	0.03	0.05–0.1	0.08–0.16
	T	0.03	0.025–0.05	0.24–0.5

For each assay/allele, the false positive signal (FPS) of the background without target allele was measured. The limit of detection (LOD) was defined in a range of the minor allele proportion where the target signal significantly exceeds the false positive signal. The limit of quantification (LOQ) was defined in a range of minor allele proportion where the coefficient of variation of the ddPCR measurements did not exceed 20%. To narrow down or precisely define the ranges of LOD and LOQ, further measurements should be performed in the respective ranges of minor allele proportions.