Description
The PAXgene Blood RNA System consists of a blood collection tube (PAXgene Blood RNA Tube) and a nucleic acid purification kit (PAXgene Blood RNA Kit). It is intended for the collection, storage and transport of blood and the stabilization of intracellular RNA in a closed tube, and subsequent isolation and purification of intracellular RNA from whole blood for RT-PCR used in molecular diagnostic testing. 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. *FOS is the gene symbol for human Fos Proto-Oncogene, AP-1 Transcription Factor Subunit. **IL1B is the gene symbol for human Interleukin 1 Beta.
The additive in PAXgene Blood RNA Tubes protects RNA molecules from degradation by RNases and other enzymes and triggers the complete lysis of all cells in the sample to minimize ex vivo changes in gene expression due to gene induction and downregulation. The result is immediate and allows long-term stabilization of RNA in specimens for up to 3 days at room temperature (see figures "RNA stability at 18–25°C: FOS "and "RNA stability at 18–25°C: IL1B") or refrigerated for up to 5 days (see figures "RNA stability at 2–8°C: FOS "and "RNA stability at 2–8°C: IL1B"). Current data shows stabilization of intracellular RNA for up to 11 years at –20°C or –70°C (see Technical Notes).
The collection of whole blood is the first step in many molecular assays used to study intracellular RNA. A major challenge in this type of testing is the instability of intracellular RNA, which rapidly degrades within hours after blood collection. Furthermore, certain transcript levels change after blood collection due to ex vivo gene regulation, such as induction and repression. Both RNA degradation and gene regulation can lead to an under- or overestimation of in vivo gene transcript levels. The PAXgene Blood RNA Tube contains an additive that stabilizes the in vivo gene expression profile by reducing post-collection RNA degradation and minimizing gene induction and repression. When used in conjunction with one of the PAXgene Blood RNA Kits, the PAXgene Blood RNA Tube provides pure RNA for accurate detection and quantification of gene expression.
Whole blood is collected directly into the PAXgene Blood RNA Tube, using standard phlebotomy practice and equipment. The RNA in the specimen is immediately stabilized for storage at room temperature, refrigerated, or frozen. RNA can be purified using one of the PAXgene Blood RNA Kits (FDA and CE). The ease of collection, stabilization of RNA at different temperatures, and elimination of additional processing steps, such as centrifugation at the collection facility and storage on ice prior to RNA purification, contributes to standardize the workflow from collection to purification, reducing variability that can be introduced by different operators (see "Reproducibility between users.")
