Table 2.

Blood collection tubes

Tube	Storage length without contamination	Storage temperature	Collection volume	Study
Cell-Free DNA BCT by Streck	7 days	RT	10 mL	a stabilizing reagent prevents cell-free DNA contamination by cellular DNA in plasma during blood sample storage and shipping as determined by digital PCR
Cell-Free DNA BCT by Streck	14 days (some contamination)	RT	10 mL	a stabilizing reagent prevents cell-free DNA contamination by cellular DNA in plasma during blood sample storage and shipping as determined by digital PCR
PAXgene Blood ccfDNA by Qiagen	7 days	RT	8 mL	performance comparison of blood collection tubes as LB storage system for minimizing cfDNA contamination from genomic DNA
Cell-Free DNA Collection Tubes by Roche	7 days	RT	8 mL	performance comparison of blood collection tubes as LB storage system for minimizing cfDNA contamination from genomic DNA
Cell-Free DNA Collection Tubes by Roche	14 days (with some contamination)	RT	8 mL	performance comparison of blood collection tubes as LB storage system for minimizing cfDNA contamination from genomic DNA
K2EDTA	24 h	RT	7.5 mL	preanalytical blood sample workup for cell-free DNA analysis using droplet digital PCR for future molecular cancer diagnostics