Diagnostic errors cause about 10% of all patient deaths and about 17% of adverse events
Source: Institute of Medicine (IOM) Report Sept. 2015
The pre-analytical phase accounts for 46% to 68% of such errors observed during the total testing process
Source: Medical Laboratory Observer, May 2014
RNA profiles are unstable in whole blood. Stabilization is key to avoiding preanalytical errors. A dedicated RNA stabilization tube should be used for blood collection.
Preanalytical steps can cause variability in RNA quality and yield, which can render results from different labs and between different operators incomparable.
The PAXgene® Blood RNA System* provides standardized methods from collection to purification.
Cellular processes can lead to altered RNA levels upon blood collection. Inhibition of such processes can be done by using stabilization reagents which lyse cells in the blood sample and protect RNA molecules from degradation by ribonucleases (RNases) and prevent induction of gene expression. Thus, RNA molecules are protected against enzymatic degradation. The result is a stabilized snapshot of the gene expression profile at the time of blood collection.
Upon blood specimen collection, ex vivo gene induction and downregulation, initiation of cell death programs, and enzymatic activity can all contribute to changes in cellular RNA transcript levels. The patented additive in PAXgene Blood RNA Tubes lyses cells in the collected blood, which effectively inhibits cellular processes that can lead to altered RNA levels. Additionally, RNA molecules are protected against enzymatic degradation. The result is a stabilized snapshot of the gene expression profile at the time of blood collection.
The proprietary stabilization reagent in PAXgene Blood RNA Tubes stabilizes intracellular RNA in collected blood specimens for 3 days at room temperature (15–25°C) and 5 days at 2–8°C. Thus, temperature fluctuations up to 25°C during transportation and storage do not impact the intracellular RNA profile and the integrity of the RNA that is subsequently purified. Furthermore, procedural variation is eliminated because collection, stabilization, transport and storage are all done in a single tube.
Differences in preanalytical methods generate variability in RNA quality and yield, which can render results from different labs and between different operators incomparable. The PAXgene Blood RNA System standardizes procedures with convenient BD Vacutainer technology, which enhances patient and healthcare worker safety, provides sample protection and facilitates consistent blood draw volumes. Furthermore, the straightforward purification workflow enables uniformity of handling to reduce user-to-user variability.
Chemistry of the PAXgene Blood RNA Kit systematically digests proteins, filters out cellular debris and depletes genomic DNA through a DNase treatment step prior to eluting RNA molecules bound to a silica membrane. The resulting eluate contains high-quality RNA with minimum carryover contaminants that can confound downstream analyses.
The graph to the left demonstrates that transcript levels of certain genes increase and decrease over time when blood is collected and stored in EDTA tubes (top). Gene expression changes are minimized with the PAXgene Blood RNA System† (bottom).
†This research was completed using the PAXgene Blood RNA System (RUO). The PAXgene Blood RNA System (IVD) was first marketed in 2005. Performance characteristics for the PAXgene Blood RNA System have only been established with FOS and IL1B gene transcripts. The user is responsible for establishing appropriate PAXgene Blood RNA System performance characteristics for other target transcripts.
Watch our on-demand RNA webinar
Enhancing the Preanalytical Blood RNA Workflow for Molecular Diagnostic Testing
By Dr. Kalle Günther
Associate Director, PreAnalytiX/QIAGEN
Blood specimens in PAXgene Blood RNA Tubes can be stored for 11 years at -20°C or -70°C. Learn more in our technical note.
* The PAXgene Blood RNA System is available for IVD use only when the PAXgene Blood RNA Tube (762165) is used in combination with the PAXgene Blood RNA Kit (762164 or 762174)