Preserving tissue specimens depends greatly on the intended use and available resources. Several methods ensure the sample's integrity for future analysis.
Common Preservation Methods
The most common methods for preserving tissue specimens in the field include:
- Freezing: Using liquid nitrogen is a reliable way to preserve tissue, particularly for molecular studies. This method is effective for long-term storage.
- RNA Later: This reagent helps to stabilize RNA within the tissue, essential for gene expression analysis.
- Ethanol (≥95%): A widely used fixative, especially suitable for preserving morphological structures.
The optimal choice hinges on factors such as the research goals, ease of transport, and any applicable regulations.
Formaldehyde Fixation: A Standard Approach
Formalin-fixed paraffin-embedded (FFPE) tissue is a standard preservation technique in pathology. This process involves:
- Fixation: Treating the tissue sample with formaldehyde, a fixative that maintains tissue morphology by cross-linking proteins. A crucial step, ensuring the sample's structure remains intact. A ratio of at least 2:1 formalin to tissue is recommended for optimal results. Source: Specimen Handling for Specific Tissue Types and Diagnostic Tests
- Processing: Involves dehydration and embedding the tissue in paraffin wax for easy sectioning. This method is frequently used for histopathological examination. Source: Tissue Processing Overview: Steps & Techniques for Histopathology
- Storage: Properly labeled and stored to maintain integrity.
Additional Considerations
- Storage Containers: Utilize appropriate containers, avoiding cardboard if possible, opting instead for plastic or polycarbonate boxes for consistent storage and handling. Source: Tissue Manual | Collecting, Handling, & Storing Tissues – Handbook
- Storage Conditions: Short-term storage might involve refrigeration, while long-term preservation often necessitates freezing. Source: How to Collect and Preserve Tissue Samples | Stirling Ultracold
- Legal Requirements: Be aware of any state or federal regulations concerning the storage duration of pathology samples. Source: How Biopsy and Cytology Samples Are Processed | American Cancer Society
Remember, careful handling and precise adherence to protocols are vital for reliable tissue preservation.
