Table 5. Comparison of L-PCR with ddPCR.

Patient	Mutation	L-PCR Mutation/wild type %	ddPCR Mutation/wild type %	Disease status
7A	c.1676T>A	0,0019	1,95	Localized		Before start of treatment
7B	c.1676T>A	0,0024	0	Localized		1 week treatment imatinib
7C	c.1676T>A	0	0	Localized		4 week treatment imatinib
10A	c.1669_1674del	0	0	Localized		Before surgical treatment
10B	c.1669_1674del	0	0	Localized		3 days after surgery
15A	c.1676T>A	0,0015	0,94	Metastasized		Before start of treatment
15B	c.1676T>A	0,0012	5,60	Metastasized		2 weeks treatment with imatinib
15C	c.1676T>A	0	0	Metastasized		6 weeks treatment with imatinib

To evaluate the sensitivity of our assay, multiple samples of three patients were analysed with the earlier described L-PCR technique. Quantitative L-PCR analysis was performed on 1 ml plasma as reported previously [Maier et al., 2013]. Four samples were scored low-level positive (<0,1% mutant/wild type ratio). When looked at positive/negative samples the results where –except for sample 7B- comparable with the ddPCR assay.