Figure 2. No plasma volume loss after shipping/transportation. Blood was drawn from 6 different donors in duplicate. One set was kept in the lab at room temperature and the other was packed in an insulated box and shipped from Thorold, ON via overnight air freight to Winnipeg, MB and then back to Thorold ON (elapsed time 72 h). Upon return, preserved samples were stored at room temperature for 7 days before plasma was separated. The plasma volume recovered from Norgen's cf-DNA/cf-RNA Preservative Tubes Dx did not change before shipping or after shipping (6-7 mL recovered plasma). For both Competitor tubes and EDTA tubes the plasma volume recovered before shipping was ~ 4 mL and after shipping was ~ 2.5 mL.

Figure 3. Hemolysis of collected blood measured over time. Blood samples were drawn into: 1) EDTA tubes, 2) Competitor tubes and 3) Norgen's cf-DNA/cf-RNA Preservative Tubes Dx and stored for up to 30 days. Hemolysis was determined by measuring the absorption of free hemoglobin in plasma from 3 subjects at 414 nm over several time points. Mean absorption is shown. The amount of free hemoglobin increased rapidly with each additional storage day in the EDTA tubes and Competitor tubes, and remained relatively constant in Norgen's cf-DNA/cf-RNA Preservative Tubes Dx.

Figure 4. Prevent cell lysis and the release of gDNA and accumulation of apoptotic ladder in plasma. Blood samples drawn into three different tubes (Norgen's cf-DNA/cf-RNA Preservative Tubes Dx, EDTA, and Competitor) and stored for up to 30 days. Norgen's cf-DNA/cf-RNA Preservative Tubes Dx helps prevent the release of high molecular weight gDNA into plasma while also minimizing the accumulation of contaminating apoptotic ladder from dying peripheral blood leukocytes. As indicated in the black circle, gDNA contamination is at a very low level as compared to both the Competitor and EDTA tubes. This is indicative of very low levels of cell lysis and subsequent release of gDNA into the preserved plasma sample.

Figure 5. Effect of high temperature (37°C) storage for 8 days. Blood samples were drawn into either EDTA tubes, Competitor tubes or Norgen's cf-DNA/cf-RNA Preservative Tubes Dx and stored at 37°C. cf-DNA was then isolated from processed plasma. gDNA concentration was determined by real-time PCR using a long ALU gene target (247 bp). The gDNA - target in EDTA tubes showed a significant drop in the Ct. value after 1 day of storage at 37°C compared to the initial time point, and continued to drop until the 8th day of storage. For Competitor, the gDNA - target remained stable up to the 4th day of storage and then the Ct. values started to significantly drop, indicating poor stabilization beyond day 4. Norgen's cf-DNA/cf-RNA Preservative Tubes stabilized samples for 8 days.

Figure 6. High Quantity of cf-DNA from Plasma preserved using Norgen's cf-DNA/cf-RNA Preservative Tubes Dx. Blood samples from the same donor were drawn into either Competitor tubes or Norgen's cf-DNA/cf-RNA Preservative Tubes Dx and stored at room temperature for 7 days. Norgen's cf-DNA/cf-RNA preservative Tube Dx recovered 6.5mL plasma whereas the Competitor's tube recovered 3.5mL plasma. The cf-DNA was then isolated from the entire plasma volume recovered from each tube using Norgen's Plasma/Serum Cell-Free Circulating DNA Purification Midi Kit (Cat. 55600) and Norgen's Plasma/Serum Cell-Free Circulating DNA Purification Maxi Kit (Cat. 55800). The quantity of DNA recovered from both samples were assessed using the Agilent Bio-analyzer High Sensitivity DNA Chip. As can be seen in the bioanalyzer trace, Norgen's  preservative tube yielded more cf-DNA (Blue peak) as compared to the cf-DNA recovered from the Competitor's preservative tube.

Figure 7. Effect of ambient temperature storage on cf-RNA, exemplified by the 18S rRNA transcript, HPRT1 mRNA transcript and miR-21. Blood samples were drawn into either: 1) Competitor tubes or 2) Norgen's cf-DNA/cf-RNA Preservative Tubes Dx. Competitor’s tubes were stored at room temperature for 14 days whereas Norgen’s cf-DNA/cf-RNA Preservative Tubes Dx were stored for 30 days at room temperature.  At the indicated times each tube was processed and the plasma was separated. Cf-RNA was isolated and the stability of the purified cf-RNA was determined by rt-qPCR amplification targeting the 18S rRNA transcript, HPRT1 mRNA transcript and miR-21. Levels of these three targets should stay the same for the duration indicating stabilization. Competitor showed significantly higher Ct values for the three targets after 7 days indicating cf-RNA degradation, whereas cf-RNA was stable for 30 days at room temperature for Norgen's cf-DNA/cf-RNA Preservative Tubes Dx.