B-188 Functional Performance Studies of Synergy Blood Collection Tube in preservation of cell free DNA, RNA and genomic DNA
Authors: Maksud I , Weikart C 
Published: October 2024

Abstract

Background
The Synergy blood collection tube was recently launched by SiO2 Materials Science to address unmet needs in the molecular diagnostics industry. The Synergy preservative satisfies product performance claims including: 1. Preservation of cf-DNA (cell free DNA) and genomic DNA for 30 days at ambient temperature 2. Preservation of RNA for 7 days at ambient temperature 3. Paired testing of cf-DNA with gDNA/RNA from the same tube. In this study, three lots of Synergy blood collection tube (BCT) were sent to a blood donation center for blood collections and shipped back to SiO2 for stability testing. The study objective was to determine the functional performance of the Synergy preservative in stabilizing human whole blood by preventing hemolysis, providing consistent plasma yield and stabilizing cell free DNA and genomic DNA for 30 days and cellular RNA for 7 days.

Methods
The performance of the Synergy preservative was benchmarked against the market leader for each of the three analytes (PAXgene RNA tube for cellular RNA, Streck cfDNA tube for cfDNA and BD vacutainer (EDTA) for gDNA). Blood draws were scheduled and performed by BioIVT and shipped same day. Upon arrival, they were incubated at ambient temperature (18-25C) for predetermined time points. At each time point, the Synergy tubes were spun down, and plasma portion was separated from the blood cell pellet. Analytes were extracted on the same day followed by quality testing. Each analyte’s benchmark stability comparison was performed using 3 matched donors, so that biological variation from different individuals can be captured. In addition, the blood tubes performance comparisons (Synergy vs market competitors) were done on the same blood samples (from the same 3 donors). Cellular RNA, genomic g-DNA, and cell-free cf-DNA were monitored for stability over a period of 7 days for RNA and 30 days for cf-DNA and g-DNA.

Results
Sample processing and extractions for three lots of Synergy tube samples provided the following aggregate results: 1. Hemolysis level remained less than 0.5 absorbance (spectrophotometric measurement at 414nm) throughout 30 days. 2. Blood draw volume &gt; 8.1 mL (which also contained the 1.4 mL of preservatives pre-filled in the tube). 3. % plasma are consistent over time, approx. at 60%. 4. 7 days stability for RNA displayed by BioAnalyzer RIN &gt; 5 (indicator of sufficient intactness of extracted RNA samples), high consistent Yields via Qubit &gt; 10 µg/tube, and A260/280 with Nanodrop = 1.8 - 2.2 (indication of highly purified RNA). 5. 30 days stability for cfDNA displayed by BioAnalyzer DIN &lt; 0.5 (indicator of pure cfDNA samples with minimal gDNA contaminations) and good Yield between 3 and 6 ng/mL of plasma. 6. 30 days stability for gDNA displayed by Qubit high Yield of 20 µg/mL, Nanodrop A260/280 = 1.8 - 2.2 (excellent purity), and qPCR DIN &gt; 0.5 (indication of intact long 222bp gDNA fragments vs short 90bp fragments).

Conclusions
Functional performance of three lots of Synergy BCT meet the specifications whereby cell free DNA, genomic DNA and RNA are stabilized with minimal hemolysis and consistent plasma yield.