Isolation and Quantification of Plasma Circulating Tumor DNA from Melanoma Patients

In recent years, circulating tumor DNA (ctDNA) has emerged as a promising prognostic and monitoring biomarker of various cancers, including melanoma. However, sensitive methods are required for its preservation, isolation, and detection. Here we describe a sensitive method for plasma ctDNA isolation using a column-based extraction kit, followed by quantification using a single mutational target with a droplet digital PCR system. This sensitive protocol has been successfully used to quantify diverse mutations present in plasma-derived ctDNA from cancer patients. The full procedure, from blood processing to the analysis of results, takes approximately a day of work.