Develop a protein-based biomarker multiplexed lateral flow assay (LFA) as a rapid qualitative radiation/nuclear biodosimetry triage device (RapidRadDx) that can distinguish between exposed and unexposed individuals in a mass-casualty ionizing radiation (IR) incident as early as 24 hours post-exposure and continuing out to 72 hours. The protein biomarker assay is intended for field use, detecting a novel plasma-soluble biomarker panel in small volumes of capillary blood samples obtained using minimally invasive finger pricks.