Background: The complement immune system is implicated in many acute and chronic inflammatory conditions and autoimmune diseases, including neurological (Alzheimer’s and multiple sclerosis), renal (lupus nephritis and glomerulonephritis), ocular (age-related macular degeneration), and systemic (lupus and rheumatoid arthritis). The complement protein C3d resides covalently attached in inflamed tissues, and it is an excellent biomarker target for complement-mediated inflammation, even at early disease stages prior to clinical manifestations. Brief Description: UCR researchers have discovered several small chemical compounds with intrinsic fluorescence properties that bind to complement C3d. These compounds can serve as molecular biomarkers for the detection of complement activation using fluorescence imaging. The compounds can be developed to become noninvasive in vivo diagnostics of complement-mediated inflammatory and autoimmune diseases, for spatiotemporal monitoring of disease progression, and for delivering therapeutics to sites of inflammation.