Fig. 1
![Fig. 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13104-022-06056-6/MediaObjects/13104_2022_6056_Fig1_HTML.png)
Rational primer and probe design for ddMSP. A Graphical abstract of the detection system. B The prediction of CpG islands was performed using MethPrimer software. Cytosine bases that can be methylated are indicated in red, and the CpG island is presented in the blue area. C Sequences of the primer pairs and probes used in each assay, amplicon size, and the genome position. ccfDNA circulating cell-free DNA; ddMPCR droplet digital methylation-specific polymerase chain reaction