The PAXgene Tissue FIX Container (50 ml) enables fixation and stabilization of tissue specimens (up to 4 samples with a maximum size of 4 x 15 x 15 mm placed into 4 standard tissue cassettes, or a single tissue sample with a maximum size of 20 x 20 x 20 mm). PAXgene Tissue FIX Containers (50 ml) are single-chamber containers prefilled with 50 ml of PAXgene Tissue FIX. PAXgene Tissue FIX rapidly penetrates and fixes the tissue, preserving tissue morphology. Fixation is comparable to formalin fixation, but without the destructive nucleic acid crosslinking and degradation. After fixation, PAXgene Tissue FIX is removed and replaced by PAXgene Tissue STABILIZER within the same container. Nucleic acids, proteins, and morphology of the sample are stable up to 7 days at room temperature, and for longer periods at 2–8°C, or even at –20°C and –80°C. Stabilized samples can be embedded in paraffin for histological studies. PAXgene Tissue Kits and supplementary protocols provide efficient subsequent purification of RNA, miRNA, DNA, and/or proteins from the same sample.
PAXgene Tissue FIX Container (50 ml) is only to be used in conjunction with PAXgene Tissue STABILIZER.

The methods for tissue fixation currently used in traditional histology are of limited use for molecular analysis. Fixatives that contain formaldehyde crosslink biomolecules and modify nucleic acids and proteins. Such crosslinks lead to nucleic acid degradation during tissue fixation, storage, and processing. Since they cannot be removed completely, the resulting chemical modifications can cause inhibition in downstream applications, such as quantitative PCR or RT-PCR. To enable both molecular and traditional pathology testing from the same specimen, a method is needed to stabilize molecular content and preserve morphology.
To meet this need, PreAnalytiX has developed the PAXgene Tissue System. The system consists of a fixation reagent (PAXgene Tissue FIX), a stabilization reagent (PAXgene Tissue STABILIZER), prefilled containers for tissue collection, storage, and transportation, and kits for purification of RNA, DNA, or total RNA, including miRNA. In addition, supplementary protocols for protein purification and other applications are available in the 'Resources' section of this page or at www.preanalytix.com.
PAXgene Tissue reagents in prefilled containers and PAXgene Tissue Kits provide a complete preanalytical solution for collection, fixation, and stabilization of tissue, and purification of high-quality nucleic acids for molecular research analysis.

PAXgene Tissue FIX Containers (50 ml) are single-chamber containers prefilled with 50 ml of PAXgene Tissue FIX. PAXgene Tissue FIX Containers (50 ml) can accommodate four standard tissue cassettes (not provided), which can hold tissue samples with a maximum size of 4 x 15 x 15 mm. PAXgene Tissue FIX Containers (50 ml) also offer the possibility for direct fixation of larger tissue samples with a maximum size of 20 x 20 x 20 mm.
PAXgene Tissue FIX rapidly penetrates and fixes the tissue. After fixation for 2 to 48 hours, depending on tissue size, PAXgene Tissue FIX is removed and replaced by PAXgene Tissue STABILIZER within the same container. Stabilized samples can be embedded in paraffin for histological studies. Nucleic acids and proteins can be isolated from the stabilized samples before or after embedding in paraffin. See the PAXgene Tissue Kit Handbooks for information about DNA, RNA, or miRNA, and the PAXgene Tissue supplementary protocols in the 'Resources' section of this page or at www.preanalytix.com for protein purification and other applications.

Sections of PAXgene Tissue fixed, paraffin-embedded (PFPE) tissue can be used for histological studies or extraction of nucleic acids or proteins. Purification of RNA, total RNA, including miRNA, or DNA from PAXgene Tissue fixed and stabilized tissue samples requires the use of one of the PAXgene Tissue Kits for RNA, miRNA, or DNA. Purification of protein requires the Qproteome FFPE Kit.