We analyzed cDNA of microRNA (coming from FFPE) coming from RT with Megaplex primer pools. Provided that you store cDNA in TE buffer at -80 C cDNA is stable and our results are highly reproducible. So we support PMID: 19769940.

Each time a sample undergoes a cycle of thawing/freezing you could expect some sort of degradation. So if you plan a future use, aliquoting could be an option for a better reproducibility of the results.

If you storage the cDNA was as Dr. Cristiano said (in TE buffer and -80 C) must be stable for long time, and maybe you were not using it to much time i.e., thawing/freezing cycles. In the opposite case some degradation can occur; due that, I recommend you to check the cDNA in the NanoDrop before to use and you can compare with the previous data if you have it. Good luck in your future work,

Hi, Doreen; I use to synthesize cDNA from plant microRNAs following the "stem-loop" procedure (PMC1292995) and found that 1/20 dilution in water is rather stable. Even after several thaw/freeze cycles housekeeping genes are amplified OK after -20°C storage for months.

Of cuorse, maintaining samples at -80°C would be better.