National Jewish Health and University of Colorado School of Medicine 1 article published in JoVE Immunology and Infection Using RNA-interference to Investigate the Innate Immune Response in Mouse Macrophages Lesly De Arras1, Brandon S. Guthrie1, Scott Alper1 1Integrated Department of Immunology and Integrated Center for Genes, Environment, and Health, National Jewish Health and University of Colorado School of Medicine In this protocol, we describe methods to efficiently transfect murine macrophage cell lines with siRNAs using the Amaxa Nucleofector 96-well Shuttle System, stimulate the macrophages with lipopolysaccharide, and monitor the effects on inflammatory cytokine production.