PAXgene TissueFIX Cont. (50 ml) Kit

A formaldehyde-free fixation system from QIAGEN, manufactured for PreAnalytiX, is designed to preserve tissue morphology and the integrity of nucleic acids without the destructive crosslinking found in formalin-fixed specimens. The single-chamber container is prefilled with 50 mL of PAXgene Tissue FIX reagent, which contains methanol, and rapidly penetrates tissue at a fixation rate of approximately 1 mm in 30 minutes.

Up to four standard tissue cassettes can be placed inside the container; when used this way the maximum sample size is 4 × 15 × 15 mm. Larger samples up to 20 × 20 × 20 mm can be fixed directly without cassettes. After fixation, tissue must be transferred to PAXgene Tissue STABILIZER, where nucleic acids, proteins, and morphology remain stable for up to 7 days at room temperature (15–25°C) or up to 4 weeks at 2–8°C. Longer storage is possible at –20°C (–15°C to –30°C) or –80°C (–65°C to –90°C) without negative effects. For paraffin embedding, dehydration should begin with at least 70–100% ethanol, low-melting paraffin (≤56°C) is recommended, and samples should not be incubated in liquid paraffin for more than 3 hours. PFPE blocks may be kept short-term at 2–25°C, but storage at –30°C to –15°C better preserves morphology and biomolecule integrity.

Nucleic acids purified with the matched PAXgene Tissue kits are free of crosslinks, with average A260/A280 ratios above 1.7 for DNA and above 1.8 for RNA and miRNA, making them suitable for demanding downstream applications such as RT-PCR, long-range PCR, and next-generation sequencing. The containers are shipped at ambient temperature and may be stored at room temperature or refrigerated (2–25°C) until the expiration date on the box label. For research use only; not for use in diagnostic procedures.