I used OLIGO dt primer to synthesize cDNA as usual. Then I remembered this time my RNAs were viral. Although there was a Poly(A) treatment step in my viral RNA isolation protocol, I am still very anxious about the results. Before doing PCR I thought I had no proper cDNA to get a result. But then I got some, which gave me some unexpected results. When I ran my samples in gel after Real Time PCR, I saw that product length of my controls (71bp) were a bit higher than I expected (almost more than 100 bp). There were no primer dimers. Then, I ran my gel some more to see the band placement more clearly, and to understand whether it was caused by the ladder or. But the bands pointed to the same place. Could this be the result of OLIGO dt usage?