Background: Tumor specimens are valuable and beneficial for medical research. Effective storage is critical for the quality of frozen tumor specimens for successful outcomes. Long-term preservation of tissues can impact RNA more than DNA or protein. Thus, the quality of RNA needs to be maintained from the beginning of tissue collection until its utilization.
Objective: The present study evaluated the purity and yield of tumor specimens stored at -80°C in the Biorepository Unit from 2010 to 2019.
Materials and Methods: Fresh frozen tumor tissues of colon, liver, cervix, and lung from several cases were annually qualified using a Nanodrop spectrophotometer.
Results: We found that the optical density (OD) 260/280 ratio of RNA from all specimens remained more than 1.8. Preservative periods of 1 to 9 years did not affect purity of RNA from tissues. Additionally, RNA yields of tumor tissues were in the range of 0.89 to 15.10 μg/mg depending on the tissue type.
Conclusion: The results of the present study suggest that the frozen specimens from Biorepository Unit were properly preserved for the long-term and yielded quality RNA.

Keywords: RNA purity, RNA yield, Tumor tissue, Biorepository