Figure 3.

Blood collection tube type and time till processing affect the levels of cfDNA MNA detection. (A) Normal blood samples collected in EDTA (E), Streck (S), and PAXgene (P) tubes, spiked immediately with Kelly cell line DNA, and processed to plasma at the indicated time post venipuncture with or without agitation. (B) Matched samples collected from patients diagnosed with MNA-neuroblastoma at initial presentation prior to treatment (diagnosis) or at disease recurrence, and at after 1 cycle of chemotherapy. Blood was collected in EDTA (E) and Streck (S) tubes and processed at the indicated time post venipuncture (in brackets) after incubation at room temperature without agitation. Following cfDNA extraction from plasma MYCN copy number (navy, left Y axis, values showed on outside end) and THNSL2 concentrations (grey, right Y axis) assessed by duplex ddPCR and presented with 95% CI.