The choice of the right transfection reagent is critical for experimental success. Liposomal systems can work well for commonly used cell types, but are sometimes accompanied by high cellular toxicity and activation of aberrant stress responses in transfected cells due to excessive membrane changes. Non-liposomal polymeric delivery systems are emerging that can efficiently deliver both DNA and smaller nucleic acids such as siRNA/micro RNA, out of the endosome and into the cytoplasm. Watch this Bench Tip Video to learn how these transfection polymers work.