The indicated transfection reagents have been found to be highly effective in transient transfection of short RNA and DNA based oligonucleotides to a variety of cell types. Leu-Fect B is ideal for modification of lymphocyte-like, suspension-growing cells. ALL-Fect and Prime-Fect are suitable for modification of attachment-dependent cells. In all cases, we recommend the users to inspect our Reagent Selection Guide (http://rjhbiosciences.com/transfection-reagent-selection-guide/) to determine the suitable reagent for the cell model to be used. All reagents are synthetic amphiphilic polymers that are selected for delivery of short oligos after extensive testing of amphiphilic polymer libraries. They are capable of undergoing multivalent interactions with oligonucleotides and encapsulating co-incubated oligos into ~100 nm particles with a net positive charge. The complexation between the oligos and the transfection reagents occurs in aqueous buffers, obviating the need for organic solvents during preparation. All reagents are non-integrating carriers, so that the genetic make-up of host cells is not altered after treatment with these reagents. ALL-Fect and Prime-Fect have been tested and found effective for plasmid DNA delivery as well as in certain cell types so that they can be used in combination delivery of large and small oligonucleotides. As with all transfection reagents, formulations of the reagents with oligonucleotides may need to be optimized for specific cell types and transfection conditions.