Optimization of Preanalytical Variables for cfDNA Processing and Detection of ctDNA in Archival Plasma Samples

Figure 1

Workflow and experimental design for evaluating cfDNA yields affected by blood collection tubes (BCTs), storage times, and centrifugation regimes. RT: room temperature. Fresh purified samples are framed by green color while samples stored for 1 h, 4 h, and 24 h before plasma separation and freezing are framed with red color. The storage at RT refers to EDTA BCTs, which were at 4°C for 24 h before plasma separation. Each step is performed in technical duplicates obtained from the same BCT for corresponding storage time and centrifugation regime.