cDNA linear or circular?

Hi,

I have a question about your answer. Why RT enzymes with reduced RNase H activity can synthesize multiple rounds of cDNA on circRNA? I think cDNA can bind to RNA, so it will stop when the full circle is completed.

Thank you for following our article. The random hexamers can bind anywhere on the circRNA sequence and the RT enzyme can produce cDNA until it completes the full circle. However, the RT enzymes with reduced RNase H activity can synthesize multiple rounds of cDNA on circRNA. The cDNA is always linear without end ligation. The PCR amplicon spanning the back splice junction is a small portion of the mature sequence of circRNA. Since a random primer can start cDNA synthesis from anywhere on the circRNA sequence, it is possible to get linear cDNA spanning the backsplice junction which can be amplified by the divergent primers.

Thanks,

Amaresh