An overview of plasma-seq. Blood is drawn from the patient, plasma prepared and the plasma DNA is isolated. The shotgun library is then prepared for sequencing. This step takes a total of 24 hours to perform. Shallow sequencing of the plasma DNA using an Illumina MiSeq machine takes about 12 hours to perform. Finally, alignment of the DNA sequences and analysis of the resulting data take between 2 and 3 hours. bp, base pair; ctDNA, circulating tumor DNA.