Next generation sequencing has developed rapidly in recent years.At present,there are a number of clinical automated sequencing systems in the market,breaking through the limitation of detection technology for circulating tumor DNA(ct DNA).The detection of ct DNA and circulating tumor cell(CTC) is of great significance for optimizing the clinical treatment of colorectal cancer.Especially the application of ct DNA and CTC has been very close to the clinical practice and proved to be better than the existing ...