DNA products such as plasmid/minicircle DNA can serve as primary part of DNA vaccine products or as important raw material for viral vectors or DNA vector of gene therapy, and for viral vector or non-viral vector of cellular immunotherapy. Residual RNA in these DNA products may affect biological activity of these products (such as interfering with plasmid transfection and expression efficiency) or pose risks (such as triggering immune responses by activating the cellular interferon pathway due to exogenous