Can tissue samples be stored in preservation solution?

Answer:
Tissue storage solutions are recommended only for short-term transport and are not suitable for long-term storage, particularly for RNase-rich tissues (e.g., spleen).

Fresh samples are always preferred, as they best preserve cell viability and RNA integrity. Tissues with high endogenous RNase activity may undergo rapid degradation even during short-term storage (e.g., within 24 hours).

Therefore, for RNase-rich tissues, storage in preservation solution is not recommended, and fresh processing or snap-freezing is preferred.

If temporary storage is required for transport:

• Place washed tissue into a tube fully filled with tissue storage solution
  (e.g., MACS Tissue Storage Solution; RNA stabilization reagents or fixatives must NOT be used) 
• Transport time ≤6 hours:
  Use wet ice, ensuring the sample tube is fully surrounded 

• 6≤ Transport time ≤48 hours:
  Use cold packs (−20°C pre-cooled, not −80°C) 
  • Wrap the sample tube (do not allow direct contact with ice packs) 
  • Place in an insulated container with multiple cold packs 
  • Avoid freezing the tissue during transport 

Important:
RNA preservation reagents and fixatives (e.g., RNALater, RNA Keeper, RNAstore) should NOT be used in this workflow.