The uses of nucleic acid delivery have expanded from recombinant gene expression to a diversity of other experimental applications, including gene knockdown with small interfering RNAs (siRNA) and genome editing with CRISPR ribonuclear protein complexes (RNPs). With these advances, three approaches have become a mainstay for delivering nucleic acid cargo into mammalian and insect cells: chemical transfection, viral transduction, and electroporation. We will highlight the primary benefit associated with each method to help you identify the best approach for a given experimental application and available laboratory resources. No single delivery method is ideal for all situations, but researchers may routinely employ a suboptimal approach for the sake of familiarity or to avoid any start-up costs associated with new methods. In addition to describing these three methods, we will introduce the Mirus Bio TransIT® transfection reagents and Ingenio® EZporator® Electroporation System, which are both easy to use and cost-effective.