Addgene is a nonprofit plasmid repository located in Watertown, Massachusetts. Addgene’s mission is to accelerate research and discovery by improving access to useful research materials and information. Addgene facilitates the sharing of high-quality scientific materials, research reproducibility, and open science by archiving and distributing DNA-based research reagents and associated data to scientists worldwide. Addgene’s repository contains over 70,000 plasmids, including special collections on CRISPR, fluorescent proteins, chemogenetics, optogenetics, and viral plasmids. All plasmids in Addgene’s repository were deposited by your scientific colleagues from around the world. There is no cost for scientists to deposit plasmids, which saves time and money associated with shipping plasmids themselves. All plasmids are fully sequenced for validation and sequencing data is openly available. Addgene also provides ready-to-use AAV and lentiviral preparations of commonly requested plasmids as a service to scientists. Addgene offers free online educational resources and protocols about molecular biology topics such as common vector backbones, cloning, CRISPR, AAV and lentivirus production, and science careers. These resources include the Addgene blog, eBooks, guides, videos, and a podcast series.