In the event of acute radiation exposure, absorbed dose may be unknown and biodosimetry tools are needed by first responders to properly triage patients. We evaluated two protein markers – FMS-related tyrosine kinase 3 ligand (Flt3L) and granulocyte colony-stimulating factor (G-CSF) – that are known to be elevated after an acute radiation exposure, as well as total white blood cell (WBC) count changes pre- and post-irradiation at different dose-rates. Female B6D2F1 mice were divided into one sham-irradiated control group and four total-body irradiated groups. Experimental groups received a total dose of 8 Gy of ⁶⁰Co gamma photon irradiation at four dose-rates: 0.04, 0.15, 0.30, & 0.47 Gy min^-1. Blood samples from mice were collected at 24 and 48 hours post-exposure for WBC and protein biomarkers (Flt3L and G-CSF). Flt3L values at all dose-rates except 0.15 were significantly elevated from controls but not each other. The G-CSF levels in mouse groups of 0.47 Gy min^-1 and 0.04 Gy min^-1 were significantly different from controls, and 0.15 Gy min-1 significantly differed from 0.47 Gy min^-1. WBC changes from baseline showed that all experimental groups were significantly lower than controls, and additionally the 0.04 Gy min^-1 group was significantly lower than the 0.30 Gy min^-1 group. Though more research is needed, it would appear that at the fixed dose, dose-rates, and time points chosen herein may not be particularly strong or show predictable differences in the selected biomarker expression levels.

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