PAXgene Blood DNA Tubes

DNA isolated using the PAXgene Blood DNA System has an A₂₆₀/A₂₈₀ ratio of 1.7–1.9. Fragments are 20–200 kb in size, with an average length of 50–150 kb (see figure "High quality and high molecular weight of genomic DNA"). Average DNA yields are 150–500 µg, depending on the number of nucleated cells present in the blood sample. Purified DNA can be used for PCR and quantitative, real-time PCR (see figure "Efficient multiplex PCR of 3 mitochondrial genes").

The PAXgene Blood DNA System is an integrated and standardized system for collection and stabilization of whole blood specimens and isolation of their genomic DNA. The system requires the combined use of PAXgene Blood DNA Tubes for blood collection and stabilization, followed by DNA isolation using the PAXgene Blood DNA Kit.

Blood is collected into PAXgene Blood DNA Tubes, which contain a proprietary blend of reagents that both prevents blood coagulation and stabilizes white blood cells. Blood samples can be stored in the tubes for up to 14 days at room temperature. DNA is isolated from the tubes using appropriate buffers supplied in the PAXgene Blood DNA Kit. Highly pure genomic DNA is obtained, suitable for use in a wide range of downstream applications.

The PAXgene Blood DNA procedure is shown in the flowchart "PAXgene Blood DNA procedure". Blood samples (8.5 ml) are collected in PAXgene Blood DNA Tubes, where they may be stored or transported. For DNA isolation, the blood is transferred to processing tubes (supplied already filled with cell lysis buffer), and the solution is mixed to lyse red and white blood cells. Cell nuclei and mitochondria are pelleted by centrifugation, washed, and resuspended in digestion buffer. Protein contaminants are removed by incubation with a protease. DNA is precipitated in isopropanol, washed in 70% ethanol, dried, and resuspended in resuspension buffer.

The DNA can be used in a wide range of downstream applications, including:

• PCR and quantitative, real-time PCR
• Southern blotting
• SNP genotyping
• Pharmacogenomic studies
• SNP discovery and Validation